1. Restore a backup
Import a JSON backup file to bring back your previously saved plan.
No local plan found
No plan found on this device.
SimuPlan stores plans locally in your browser. If storage was cleared, you switched browsers or devices, or you're using incognito mode, your saved plan won't appear unless you restore a JSON backup.
Sample data is not your saved plan. It's a demo workspace to help you explore SimuPlan when no local plan is available.
Local-first. Private by design.
No account required. No cloud sync. Your data stays on this device.
Welcome to SimuPlan
Let's build your first plan.
We'll walk you through a few simple steps to set up your plan. You can change anything later.
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Private
Your plan stays with you.
All your data is stored in your browser and never leaves your device. You're in control, always.
About You
Tell us about yourself and your household.
Your Finances
Add your accounts, balances, income, and cash-flow basics.
Your Goals
Define your retirement age and spending goals.
Assumptions
Review and adjust key planning assumptions.
Review & Finish
Review your plan and you're all set.
- 1About You
- 2Your Finances
- 3Your Goals
- 4Assumptions
- 5Review & Finish
About You
Start with the profile details that anchor your plan's timeline, tax assumptions, and application mode.
Application Mode
Choose the planning lane that best matches where you are today.
Your Household
Tax & Coverage Basics
Why we ask
This information helps personalize your plan and ensures our assumptions match your situation. You can update any of this anytime.
- ✓About You
- 2Your Finances
- 3Your Goals
- 4Assumptions
- 5Review & Finish
Your Finances
Capture the basics: what you have now, what comes in, and what you expect to spend.
Add your starter balances
Estimate your current totals by planning bucket. This gets the first projection moving. After setup, you can add real account details manually.
Prefer importing spreadsheets? Settings and Plan Tracking include a balance import tool and sample file format.
Have another account type? Start with the closest total here, then fine-tune the account details in Settings after the starter plan is built.
Income
Start with current earned income and any known retirement income. For a two-person household, enter combined earned income for now; you can split it later in Settings > Profile.
Start with the income sources already supporting a fully retired household. If anyone still earns wages, return to About You and choose Planning for Retirement.
Cash flow
Add the regular monthly amount you expect to save or contribute before retirement.
Set the checking balance you want to keep available for near-term bills. SimuPlan uses this as your operating-cash cushion when tracking withdrawal needs.
Why we ask
Balances, income, and cash-flow basics create the first version of your plan. Timing choices, detailed account rules, taxes, and withdrawal preferences can be refined later.
- ✓About You
- ✓Your Finances
- 3Your Goals
- 4Assumptions
- 5Review & Finish
Your Goals
Set the timing and lifestyle target SimuPlan should build around.
Retirement Timing
When would you ideally like retirement to begin?
Your household retirement plan begins today.
Different work-end dates? Enter the household's starter retirement age here. After saving, use Settings > Profile to assign each person's work-end age, earned income, and contributions.
Is anyone in the household still working? Return to About You and choose Planning for Retirement. Household Retired Now assumes everyone in the household is already retired.
Retirement Lifestyle
Start with the monthly lifestyle you want the plan to support, in today's dollars.
Need spending to change over time? You can add higher-spending go-go years, lower-spending slow-go years, and one-time retirement expenses later in Settings.
Social Security Timing
Tell SimuPlan when Social Security should begin for each person in the household.
If you are already receiving Social Security, enter your current age. You can refine claiming assumptions later in Settings.
Retirement target
Choose a useful number to plan toward.
Enter the retirement target balance you want this plan to work toward. You can change it later in Settings.
Carried over from the marketing calculator.
Suggested retirement-age target: — Complete retirement timing and monthly spending above to see an estimate.
Why we ask
Goals tell SimuPlan what the money is meant to do. Start with your best estimate now, then use Settings later for finer control.
- ✓About You
- ✓Your Finances
- ✓Your Goals
- 4Assumptions
- 5Review & Finish
Assumptions
Use balanced defaults, or adjust the few assumptions that matter most to the starter projection.
Projection & Return Assumptions
These are the starter assumptions the projection actually uses.
Returns are set by starter account bucket. You can refine individual account returns later in Settings.
Everything else starts on auto
Taxes, Social Security COLA, ACA MAGI cap estimates, Medicare age, RMD rules, penalty-free withdrawal age, withdrawal order, and spending basis use SimuPlan's starter defaults.
After the starter plan is built, Settings gives you finer control over each of these assumptions.
Why assumptions matter
Returns and inflation are the assumptions most likely to move a starter projection. Choose reasonable starting assumptions here, then use scenarios later to test different futures.
- ✓About You
- ✓Your Finances
- ✓Your Goals
- ✓Assumptions
- 5Review & Finish
Review & Finish
Name this starter plan, save it as your first scenario profile, and keep a backup option close by.
Review your values before saving.
Starter plan profile
Give this plan a name.
Saved scenario profiles let you come back to this starting point, compare future versions, and experiment without losing your baseline.
Ready to save this starter plan in your browser.
Recommended next (optional)
Add your first real balance snapshot.
The totals you entered into Your Finances are enough to get the projection started. SimuPlan comes alive when it has real account information to compare against the projection though. Consider adding that now, or later once you're in the app.
Prefer importing spreadsheets? After setup, Settings and Plan Tracking include a balance import tool and sample file format.
Keep a JSON backup handy.
A backup protects your plan if browser data is cleared. It also gives you a portable file you can load on another computer or share with a financial advisor.
Where to go next
The dashboard gives you the first readout. Plan Tracking compares any real balances you add against your projection, and Settings is where you can add detail, tune tax rules, and make the starter plan more personal.
Retirement Goal Line
Track how the latest imported balance compares with the retirement starting target you are planning toward.
Current progress
Estimated target date --
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--
Target --
Plan Pulse
A quick read on readiness, savings pace, and the projected surplus or shortfall against your retirement target.
Current-Year Pulse
Year -- status from withdrawals, estimated taxes, and MAGI-relevant taxable sales.
Monte Carlo Snapshot
Quick simulation readout from the current plan.
Waiting for the current Monte Carlo snapshot.
Paths staying funded
Half of the simulation paths finished above this ending balance and half below it.
The 10th-percentile ending balance: about 1 in 10 paths finish below this amount.
Share of paths that reached the retirement target by the planned retirement age.
Balance History Snapshot
- Latest snapshot
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- Imported total
- --
- Actual vs planned
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- Retirement target gap
- --
- Recent movement
- --
Exploratory insight
Did you know?
Every assumption is a lever.
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Once the plan loads, this space will surface a useful place to explore next.
Explore the workspaceAnnual Balance Detail
This chart mixes annual flows and ending balance in one view. Tap or click a year group to pin its six-year zoom window. With a mouse, hover to preview.
Investment growth
Withdrawals
Ending balance
Annual Balance Overview
Tap or click a year group to pin nearby years. With a mouse, hover to preview.
Growth Outpaces Withdrawals
The chart shows whether modeled growth is outpacing portfolio cash used.
Long-Term Coverage
Projected balances stay visible across the full planning window.
Explore in Detail
Tap or click a year group to pin its local window and inspect the money-flow story.
How to read this page
Long-term projection, not a daily scorecard
Projections start from the latest saved balance, then carry your plan assumptions forward to estimate whether retirement still works.
Uses current plan inputs
Assumes future contributions and returns
Does not score recent balance history
Compare with Plan Tracking
Plan Tracking can look different because it checks whether real imported balances have been matching the plan month by month.
Projection Milestone Path
Follow the portfolio from today, through the retirement transition, to the end of the active planning window.
Today
--Starting point across the active household accounts.
Retirement
--Projected balance where the plan switches phases.
End
--Final year in the active projection window.
Projection Summary
These cards are driven primarily by your plan inputs and assumptions, using your latest saved balance snapshot as the current starting point when balance history is available.
Retirement destination
This row compares your retirement target with the planner's projected balance, then expresses the surplus or shortfall in months of planned spending.
Current savings engine
This row shows how your current income and contribution plan are supporting progress toward your retirement goal.
Adjustment levers
This row shows the main levers you can change if you want to improve the outcome: save more, earn a higher return, or retire later.
Retirement Target Trend
Monthly balance snapshots translated into projected surplus or shortfall at retirement.
Latest surplus / shortfall
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Waiting for balance history.
Best month
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Highest projected surplus.
Months above target
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Latest snapshot per month.
Annual Detail
This view focuses on your balance path to retirement first. Subsidy and MAGI details move to the retirement health section until they become relevant.
How to read this report
This report breaks your retirement plan into a clear, year-by-year story.
1
Annual Timeline
Each row covers a calendar year; the first and last years may be partial. Click any year to open the Money Flow Story and see how that year was built.
2
Money Flow Story
See exactly how the start balance becomes the end balance. We show what added money, what used money, and the impact of taxes and withdrawals.
3
Financial Explainability Engine
Go beyond the numbers. Understand why taxes were triggered, how MAGI was built, and how taxable basis affects brokerage withdrawals.
Tip: Click any row in the timeline to open the full story for that year. The more detail you explore, the clearer your retirement picture becomes.
How to read this page
Near-term reality check, not a full re-projection
Plan Tracking compares imported balance history with where the projection expected the portfolio to be by the same month.
Uses imported balance history
Matches real snapshots to projection months
Can look worse than Projections during market drawdowns
Why this can differ from Projections
Projections may still show the plan working if future contributions, time, and return assumptions recover a short-term tracking gap.
Real balances, compared to plan
The latest imported snapshot is matched against the projection so you can see whether real balances are tracking ahead of or behind plan.
Recommended first step
Activate Plan Tracking
Your starter balances are powering the projection, but Plan Tracking needs at least one real dated balance snapshot before it can compare actual progress against the plan.
Add your first snapshot manually now, or use spreadsheet import if you already track balances elsewhere.
Portfolio Snapshot
Latest imported balance, recent movement, and how the money is grouped for planning.
Waiting for imported balance history.
Import at least two snapshots to show the comparison window.
Total Portfolio
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--
Change since prior snapshot.
Add one more monthly balance snapshot and this card will compare your most recent snapshot against the prior month.
Portfolio by Planning Bucket
Grouped to match the buckets your projection uses.
Import at least two snapshots to show the comparison window.
Are real balances helping the plan?
Imported snapshots are matched to the projection month, then compared against the plan and retirement target.
Short-term tracking vs. long-term projection
Plan Tracking compares real balances against the matched projection month. Projections carry the latest balance and assumptions forward to estimate the retirement outcome.
Suggested next withdrawal
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Add a real balance snapshot to calculate the next withdrawal suggestion.
Import balance history to compare actual balances against the matched projection month.
Add a retirement target balance to estimate the gap.
Recorded history provides the basis for plan comparisons.
Needs matched imported snapshots.
Trend-based estimate will appear once imported balance history is available.
Manage imports and backups
Keep your plan current and your data protected.
Local storage reminder
Your plan lives in this browser. Download a JSON backup before clearing browser data or switching computers.
Ready for your next balance update.Expected Return Alignment
Compare recorded investment and savings balances with the pace implied by the plan's return assumptions. Accounts need enough history and a return assumption to appear here; checking accounts set to 0% are not included.
These are annualized balance-growth estimates, not calculated investment returns. Actual pace includes every recorded balance change. Adjusted pace subtracts planned contributions over the tracking period; other balance activity and timing may still affect it. Expected pace applies the plan's current return and contribution assumptions across the full tracking period.
View Account Details
Imported accounts grouped into the same planning buckets used by projections.
Import at least two snapshots to show the account comparison window.
Balance Over Time
Planned balance (projection) versus imported actuals. The gap shows how closely your real balances are tracking against the plan.
Staying close to plan over time is a useful confidence signal that your real balances are moving in line with the projection and your inputs reflect real-world income, saving, and spending patterns.
Your health & tax planning worksheet
Record actual income, withdrawals and sales, log tax payments you’ve made, and see how those entries affect your MAGI room, withdrawal guardrail, and estimated taxes. Use this worksheet throughout the year to keep your plan connected to what you actually do.
1. Record income, withdrawals & sales
Enter money you’ve withdrawn, the account it came from, and any taxable gain or income.
2. See the impact on your plan
Review how your entries affect MAGI room, withdrawal limits, and estimated federal and state taxes.
3. Log payments & stay current
Record estimated tax payments you’ve already made and review what remains for each quarter.
Are health and tax guardrails staying in range?
Your current-year MAGI room and withdrawal room are tracked side by side, so taxable sales, spending, and subsidy thresholds stay visible before they become a problem.
MAGI Room
--
remaining
Before the tracked income cap.
0%
of MAGI cap used
You are within your MAGI limit.
Withdrawal Guardrail
--
remaining
Under the annual withdrawal guardrail.
0%
of guardrail used
You are within your safe withdrawal range.
Where is this year's MAGI coming from?
Projected retirement income, interest, dividends, taxable sale income, and remaining MAGI room are translated into a simple equation against your current-year MAGI cap.
Record Income, Withdrawals & Sales
Add actual withdrawals and sales as they happen. Your entries update the totals and guardrails above.
YTD withdrawals
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No ledger rows yet.
Withdrawal-rate used
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Based on the active guardrail.
Remaining guardrail room
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Add sale rows to calculate room.
Income included in tax estimate
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Counts rows marked for MAGI.
Quarterly Tax Workspace
Review estimated taxes and record payments you’ve already made to the IRS or your state. Recording a payment here saves it in SimuPlan; it does not send a payment.
Scenario Lab
Compare saved scenario branches, ask focused diagnostic questions, or build a temporary query against the current plan.
Choose your scenario lane
Saved scenarios are branches you can compare. Diagnostic questions are answer-first tests. Custom queries combine temporary inputs before you decide what to save.
Comparison rules
The current plan and saved scenario must use the same planning mode and simulation length so the comparison stays apples-to-apples.
Only compatible saved scenarios are shown.
Question mode
Ask the planner a specific retirement question
These questions test the current plan with focused evidence so you can understand timing, spending, taxes, withdrawal pressure, and durability.
- 1Choose categoryPick a topic to explore
- 2Review setupConfirm the selected question
- 3Review & runSee the answer and evidence
- 4View resultsExplore insights and drivers
Choose a question category
Browse categories or pick from popular questions to get started.
Popular questions
Popular questions to get started quickly.
Retirement Resilience Review
Find your plan’s toughest challenge—and what could improve it
The review runs every applicable stress test against your current saved plan. It identifies which tests stay within the review rules, ranks those that do not, and then tests practical responses against the highest-priority result.
The answer may be a change that restores the result—or confirmation that keeping your current plan is the strongest tested choice.
Stress-test your saved plan
Run applicable planning pressuresThe review tests earlier retirement, higher spending, inflation, weaker returns, large expenses, poor early markets, and other conditions your plan can model.
Separate the passes from the concerns
See which tests stay within every review ruleEach pressure is checked using randomized future paths, historical market periods, and the review’s plan-funding rules.
Identify what needs the most attention
Focus deeper review where it matters mostIf multiple tests fall below a rule, the review ranks them so the most important concern is investigated first.
How priority works: funding and survival concerns come first.Test practical responses
See what improves the selected resultThe review tries changes such as retiring later, spending less, or saving more. It shows what passed, what helped, and whether keeping the current plan was the strongest tested response.
What you will learn
- What passed
- What raised concerns
- What ranked first
- Why it mattered
- What improved it
- What to watch next
Uses your current saved plan as the baseline
Running the review does not change your plan or save any new assumptions.
A saved plan is required
Create or save a retirement plan before running the resilience review.
Open Plan assumptionsCustom query mode
Build your own query
Choose one or more temporary inputs, tune each assumption, and run them together against the current plan. Save only the results you want to keep as a scenario branch.
- 1Choose inputsPick temporary levers
- 2Tune valuesAdjust the query setup
- 3Run queryCompare with current plan
- 4Review answerUse the evidence
Temporary test setup
Choose a diagnostic question
Select a question above to build a temporary test against your current plan.
Comparison results
Choose a compatible saved scenario branch, then launch the analysis to compare it with the current plan.
Projected portfolio balance
Saved scenario branch and current plan over the full projection window.
What changed most
Strengths & trade-offs
Detailed metrics
Full scenario comparison report, including setup differences, projection outcomes, taxes, and stress-test results.
Scenario B is compared directly against Scenario A, with the Difference column showing how much Scenario B moves each metric.
Positive change
Negative change
Neutral change
| Metric | Current plan | Test result | Change |
|---|
Simulation Lab
Welcome to SimuPlan's Simulation Lab
Use Simulation Lab to stress test your current loaded plan. Begin by selecting the number of simulations to run.
Simulation Count:
Built for real-world uncertainty
Model thousands of possible futures using randomized returns and historical market data.
See the full range of outcomes
Understand upside, downside, and everything in between with clear probability bands.
Stress test with confidence
Explore market volatility, sequence of returns, and timing risk against your current plan.
Plan with clarity
Use simulation evidence to make smarter decisions and stay on track for your goals.
Simulation Lab
Choose the stress view you want to inspect
Launch simulations once, then inspect each view as a different slice of the same evidence.
One report, three different views
This triage run combines randomized futures, historical rolling windows, and famous market replays into one stress verdict, then points toward the view that deserves closer inspection.
Simulation Lab
Running simulations
Preparing the current plan.
0 seconds elapsed. Results appear after all three checks finish.
Overall stress verdict
Not run yet
Launch simulations to see the plan through three different risk views.
Overall funded percentage
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Launch simulations to total the funded paths across all views.
Randomized futures
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Waiting for randomized futures.
500 futures after launch.Launch simulations to identify the weakest randomized path.
Historical window scan
Robert Shiller data
Tests every full-length rolling block available for the projection length.
Historical windows after launch.Launch simulations to identify the weakest historical window.
Famous market replays
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Waiting for famous replay results.
Recognizable stress periods.Launch simulations to identify the weakest market replay.
Simulation paths
Explore the outcomes across simulated paths
Switch between randomized futures and rolling historical windows from the latest simulation run, then select any path to inspect its balance story and return sequence.
Simulation paths
Explore the outcomes across simulated paths
Switch between randomized futures and rolling historical windows from the latest simulation run, then select any path to inspect its balance story and return sequence.
Choose which results to explore
Switching views changes the results below. No new run is needed.
Funded paths--
Randomized futures are generated from the active return assumptions.
Median ending balance--
Half of randomized futures end above this amount and half below it.
Weak-path ending balance--
The 10th-percentile ending balance: about 1 in 10 futures finish below this amount.
Downside pressure--
Largest observed fall from a prior high across the run.
Strongest Randomized Futures
The top upside paths: strongest ending balances, then the drivers that helped them compound.
Weakest Randomized Futures
The paths most worth inspecting first: depletion, largest target shortfalls, then lowest cushion.
Outcome distribution
Ending balance distribution
Where the randomized futures cluster at the end of the planning window. Numbers above bars show futures counts.
Depleted
Funded
Futures report
All randomized futures
Review every synthetic path from the latest simulation run, then filter by outcome or select a future to inspect its balance story below.
Launch simulations to populate outcomes.
Inflation path
Choose how spending changes inside each historical window
Spending follows the monthly CPI changes aligned with every rolling market window, including deflation. This is the default recommended setting.
Running simulations…
Rebuilding every historical window with the selected inflation path.
What changes? With Historical CPI on, spending follows the month-by-month inflation path that occurred alongside each rolling market window. With it off, every window uses your plan's fixed annual inflation assumption.
Why is it recommended? Replaying returns and inflation together gives a more complete view of the purchasing-power pressure households actually faced during each period.
Why can results move either way? Inflation shocks can raise spending and withdrawals when markets are already under pressure. Lower inflation or deflation can reduce spending pressure, so some historical windows may improve.
What stays unchanged? Income sources and healthcare costs that have their own growth settings continue to use those plan settings.
Comparing an older report? Historical windows previously used your plan's fixed inflation assumption. Turn Historical CPI off to compare using that earlier methodology.
Funded windows--
The historical view scans every full-length rolling block in the annual return data.
Median ending balance--
The middle outcome across all historical windows.
Weak-path ending balance--
The 10th-percentile ending balance: about 1 in 10 historical windows finish below this amount.
Downside pressure--
Largest drawdown observed across historical windows.
Strongest Historical Windows
The top upside windows: strongest ending balances, then the historical return drivers that helped them compound.
Weakest Historical Windows
The historical windows most worth inspecting first: depletion, largest target shortfalls, then lowest cushion.
Outcome distribution
Ending balance distribution
Where the historical windows cluster at the end of the planning window. Numbers above bars show window counts.
Depleted
Funded
Historical report
All historical windows
Review every rolling historical window from the latest simulation run, then filter by outcome or select a period to inspect its balance story below.
Launch simulations to populate outcomes.
Selected replay
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Select a replay to inspect the result.
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Historical backdrop
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Key stress timeline
These are the historical pressure points this replay front-loads into the plan.
Replay verdict
--
--
--
The replay shows how market timing affects the path to retirement.
Replay balance path
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Settings
Control the details that drive your plan and see how small changes can shape your future.
Starting Balance
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Annual Contributions
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Retirement Target
--
Years To Retirement
--
Profile
Household size, birth month / year, retirement timing, and employer coverage.
Spending
Monthly spending and planned expense assumptions.
Income
Social Security, pensions, annuities, income sources, and working-year earned income.
Health / MAGI
Medicare, subsidy thresholds, MAGI deductions, and income-sensitive planning assumptions.
Taxes
Filing status, state, tax rates, Social Security taxation, and tax-estimate mode.
Withdrawal Strategy
Withdrawal methods and tax optimization rules.
Plan Assumptions
Projection years, inflation, baseline, target, and age rules.
Accounts
Account buckets, balances, return assumptions, contributions, and imported balance behavior.
Scenarios
Save versions of your plan to revisit and compare.
Data & File Management
Balance imports, starter files, reports, backups, restore actions, and maintenance tasks.
PRO TIPS
Download a fresh backup after meaningful plan edits so you always have a clean restore point.
Retirement age, monthly spending, inflation, and expected returns usually move the forecast more than fine-tuning small details.
Before changing several assumptions, save a scenario so you can compare the results in Scenario Lab.
Fresh balance snapshots make Plan Tracking more useful because the app can compare real progress against the projection path.
Profile
Update the household profile and timing assumptions that anchor the rest of the plan.
Changes save into the active plan.
Primary value--
Current assumption.
Application Mode--
Controls which fields are relevant.
Plan impactProjection
Changes flow into scenarios and simulations.
Quick navigation
Jump to another settings area without returning to the overview.
Household basics
These fields define household size, birth month / year, retirement timing, and employer coverage assumptions.
Household timing
Household work timelines
Choose one shared retirement timeline, or model when each person stops working.
Active model
Combined household
Earned income and assigned account contributions currently stop together when household retirement begins.
Income, spending, and taxes
These assumptions drive working-year savings, retirement cash flow, tax estimates, and MAGI-sensitive planning.
Related money settings
Move between focused money modules.
Current income
Used for savings-rate and working-year income diagnostics while the household is still working.
Retirement income
Social Security, pension, annuity, and recurring income assumptions that reduce required portfolio withdrawals.
Social Security
Claim age, manual or estimated benefit, spouse benefit, and annual COLA.
Other Income
Pension, annuity, and other recurring income sources.
Spending baseline
Set the household spending need that the projection tries to support.
Health and MAGI planning
Track income-cap pressure for pre-Medicare bridge years and other MAGI-sensitive planning.
Used only for the HHS FPL ACA MAGI cap estimate. This does not change tax filing, Social Security, or spouse modeling.
Tax assumptions
Auto-estimate uses filing status and state. Custom rates let advanced users override tax drag directly.
Estimated from federal brackets, filing status, and taxable ordinary income.
Estimated from federal capital gains rules, taxable brokerage activity, and NIIT when applicable.
Estimated from your selected state and the plan's taxable income mix.
Built from the active federal and state tax rules included with this app.
Account buckets
Review the active account buckets, imported balances, return assumptions, contribution settings, and tax treatment.
Plan assumptions
Set the projection window, inflation assumption, balance targets, and age-based retirement rules.
Withdrawal rules
Choose the default order for funding retirement spending and the guardrail method for Household Retired Now planning.
SimuPlan will run the standard preset.
Starts at a 4% withdrawal rate, watches a 20% guardrail band, and adjusts the next year's base spending by 10% when the plan moves outside the band.
Advanced Guyton-Klinger settings
Most users should leave these alone. Change them only when you want to compare a specific custom interpretation of the strategy.
Scenario versions
A scenario is a saved version of your plan. Use scenarios to explore different choices and return to a plan you want to keep.
Save the current plan as a scenario
Save a version of your current plan to compare with other scenarios or return to later.
My saved scenarios
Load a saved plan, make a copy, rename it, or delete a scenario you no longer need.
Compare saved scenarios
Choose two saved scenarios to see how their settings differ.
Your files and backups
Update account balances, download backups, and manage the plan data saved in this browser.
Local only
JSON backups
Balance history
1.
Bring data in
New
Update From Screenshots
Read balances from one or more account screenshots, verify every value, then save a snapshot.
Manual Balance Entry
Add a new monthly balance snapshot manually for one or more accounts.
Import Balance History
Import account balances from a CSV or XLSX file. We'll match and add the data to your plan.
Download Sample CSV
Use this example to see how to arrange dates, account names, and balances in your spreadsheet before importing.
Download sample CSV
2.
Manage & export
Download Backup
Save your plan, scenarios, tracking history and Health & Taxes records in a JSON file.
Restore from Backup
Replace your plan, scenarios, tracking history and tax records from JSON. Download your current data first to keep a copy.
Export Balance History
Export your imported balance history to CSV for your own records or for use in other tools.
3.
Storage Health
Storage Health
SimuPlan stores your data locally in your browser.
Local storage used
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Checking storage Reading browser storage usage. i Learn more about local storage
Learn More About Local Storage
SimuPlan stores your plan directly in your browser instead of on a cloud server.
This approach was chosen intentionally. It keeps your data under your control, eliminates the need for accounts and passwords, and avoids the privacy concerns that come with storing personal financial information online. Your plan never leaves your device unless you choose to export it.
Because SimuPlan is built and maintained by a single independent developer, a local-first design also avoids the cost, complexity, and security responsibilities of operating cloud infrastructure, managing authentication systems, protecting user databases, and maintaining account aggregation connections. That allows more time to be spent improving planning tools rather than maintaining backend services.
Local storage is surprisingly efficient. A typical plan containing settings, scenarios, and imported balance history often uses only a small fraction of available browser storage. The largest contributors to storage usage are:
- Imported balance history over many months or years
- Large numbers of saved scenarios
- Detailed account metadata and planning assumptions
- Custom overrides and account-level settings
Simulation results, Monte Carlo runs, and comparison reports are intentionally treated as temporary analysis and generally are not permanently stored, helping keep storage requirements small.
Most browsers provide several megabytes of storage for local applications. SimuPlan monitors usage and provides backup tools so you can export your work whenever you wish.
For added peace of mind, consider downloading a JSON backup after important imports or major planning changes. A backup allows you to restore your plan later, move it to another computer, or keep a historical copy of your work.
Your data. Your device. Your control.
PRO TIPS
Use this as the regular household spending baseline.
Choose how the monthly spending number should be interpreted.
Add larger planned expenses only when they should not be part of the monthly baseline.
Model transparency
How SimuPlan models a retirement plan
SimuPlan does not try to predict the future perfectly. It builds a clear planning model from your inputs, then shows how that model behaves under different assumptions.
The goal is to help you understand the moving parts: balances, contributions, spending, taxes, income, account types, market returns, and timing choices. When those assumptions change, SimuPlan shows how the outcome changes too.
Core model
Five ways SimuPlan checks a plan
SimuPlan looks at your plan from several angles. Each method answers a different question, so results may not always point in the same direction. That is normal, especially when markets are volatile or recent balance history differs from long-term assumptions.
Central projection
The central projection is SimuPlan's baseline path. It starts with your latest saved or imported balance, then moves the plan forward month by month, with yearly summaries, using your contributions, spending, income, taxes, inflation, account returns, and retirement timing.
Contribution timing: For projection purposes, planned monthly contributions are treated as arriving at the beginning of each modeled month, before that month's investment return is applied. Calculators that assume contributions arrive at month-end may show a slightly lower ending balance, especially over long periods. The total contributed does not change; only the timing of modeled growth differs.
What to remember: This is a planning baseline, not a market forecast.Plan tracking
Plan Tracking compares your imported real-world balance snapshots with where the projection expected you to be at the same point in time. It is a near-term reality check, not a full re-projection of the future.
What to remember: A recent month can look behind plan even when the long-term projection still recovers under current assumptions.Randomized simulations
Monte Carlo simulations create many possible market paths around your expected-return assumptions. SimuPlan can use either its standard randomized model or an optional asset-aware model based on confirmed investment mixes.
What to remember: Randomized results test market uncertainty and timing risk. They are stress tests, not guarantees.Historical windows and Market Replays
Historical Monte Carlo tests complete rolling windows of past monthly market returns across your planning horizon. Market Replay instead begins with a selected event, such as the Great Depression, then uses the plan's configured returns for the remaining years shown in its coverage summary. Both use a Robert Shiller-based market return dataset, with complete annual market history through 2025.
Inflation treatment: Rolling historical windows can replay the monthly CPI path that occurred alongside each market sequence. This is the recommended setting for a complete historical comparison. You can instead hold spending growth to the plan's fixed inflation assumption to isolate market sequence risk. Income sources and healthcare costs that have their own growth settings continue to use those settings.
Historical CPI is on by default for rolling windows. Market Replay has a separate historical CPI option that is off by default; otherwise it uses the plan's inflation assumptions. Increasing the randomized run count does not add historical windows or named replays.
What to remember: History is useful context, but future markets will not repeat the past exactly.Retirement Resilience Review
Retirement Resilience Review is SimuPlan's full-plan evaluation. It checks the saved plan against explicit funding rules, runs every applicable pressure through deterministic, randomized, and historical validation, ranks the results, and tests practical responses against the highest-priority concern.
Where to find it: Open Scenario Lab, choose Run resilience review, and start the review from that panel.
What to remember: This is a synthesis of SimuPlan's existing models—not a fifth projection engine—and it does not change the saved plan.Investment mix across simulations
How investment mix changes simulation results
The investment mixes in Settings → Accounts apply to Randomized Monte Carlo, Historical Monte Carlo, and Market Replay simulations once the optional setup is complete. Randomized paths still begin with your expected-return assumptions; historical periods use market history at the selected mix.
If any funded investment account that needs clarification does not have a confirmed investment mix, SimuPlan uses its standard randomized model for the entire run. This model varies account returns around the plan's expected-return assumptions without trying to identify the stocks and bonds held inside each account.
This remains the default so users can create and test a plan without researching account allocations first. With incomplete mix setup, historical windows and market replays also retain the legacy approach: they infer a stock/bond mix from each planning account's expected return rather than using partially confirmed holdings. Legacy cash accounts keep their configured yield.
Once every flagged funded account has a confirmed investment mix, SimuPlan weights those mixes using the accounts' current balances. Each randomized future then creates shared stock, bond, and cash market movements. Accounts exposed to the same type of investment can rise and fall together instead of receiving unrelated market results.
An account identified as single-company stock also receives additional generic concentration risk. SimuPlan does not forecast or replay the performance of the named company.
Imported accounts are grouped into the plan's account buckets. Their current balances determine the combined mix within each bucket. That mix stays fixed during a run; the household's overall exposure can still change as bucket balances change. This is a broad allocation model, not a simulation of individual holdings or trades.
How historical investments are represented: Stocks and bonds follow broad market history. Individual stocks and alternative investments use broad stock-market returns rather than their own historical performance. Historical runs do not add the randomized model's extra single-company risk. All-cash buckets use their configured return; cash within a mixed bucket is treated as cash without additional growth. After a Market Replay's historical period ends, the remaining years follow the plan's configured returns.
These allocation rules apply wherever the full plan requests simulations, including Simulation Lab, Scenario Lab comparisons, Retirement Resilience Review, and applicable Plan Report results. SimuPlan does not combine the two randomized models within one run. If a new funded account needs a mix—or an existing account is changed back to “Not confirmed”—the standard randomized model and legacy historical allocation are used until setup is complete again. Rerun simulations and reviews after changing mixes to compare results for the updated plan.
Full-plan review
How Retirement Resilience Review evaluates a plan
The review is designed to answer a broader question than one scenario or simulation: which tested condition deserves the most attention, why did it matter, and what practical responses improved the result?
Evaluate the saved plan
The current plan is checked first. Planning for Retirement and Household Retired Now use different, mode-appropriate funding rules.
Validate every applicable pressure
Each supported pressure receives the same deterministic projection, randomized future paths, and rolling historical-window review. Historical windows use historical CPI when that data is available.
Rank the results
The review gives priority to central-projection depletion, then portfolio-survival failures, the number of missed rules, and the size of the largest rule shortfall. A consistent tie-breaker resolves otherwise equal results.
Test practical responses
Applicable responses—such as changing retirement timing, spending, saving, income, or spending flexibility—are rerun against the highest-ranked pressure using the same validation process.
Planning for Retirement
Four review checks
- Full retirement goal: At least 70% of validated paths must reach the user-entered retirement starting target and remain funded afterward.
- Central retirement starting balance: The deterministic projection must reach at least 90% of the user-entered retirement target.
- Portfolio survival: At least 85% of validated paths must retain portfolio money through the planning period.
- Central projection funded: The deterministic projection must retain portfolio money through the full planning period.
Household Retired Now
Three review checks
- Weak-path ending reserve: The weak-path ending balance must retain at least 75% of the review reserve benchmark. That benchmark is five years of entered monthly spending, with a $250,000 minimum.
- Portfolio survival: At least 85% of validated paths must retain portfolio money through the planning period.
- Central projection funded: The deterministic projection must retain portfolio money through the full planning period.
Rules and boundaries
How SimuPlan handles taxes, Social Security, Roth conversions, and Household Retired Now planning
SimuPlan includes enough detail to support useful planning comparisons without trying to become tax software, Social Security filing software, or a professional advisory system. The goal is to help you understand the tradeoffs, spot important planning questions, and know when something deserves a closer look.
Tax planning estimates
SimuPlan estimates the major tax items that commonly affect retirement planning: federal ordinary income tax, capital gains and dividends, state tax, taxable Social Security, MAGI, ACA MAGI room, IRMAA room, RMD effects, and selected retirement-income exclusions.
What to remember: These estimates are designed for planning comparisons. They do not cover every deduction, credit, local tax, estate rule, inherited-account rule, or future tax-law change.
Social Security estimates
SimuPlan can estimate primary and spouse benefits, compare claiming ages, and apply annual Social Security cost-of-living adjustments.
What to remember: SimuPlan helps compare broad claiming choices, but it does not yet perform full household claiming optimization, survivor benefit optimization, or every Social Security edge case.
Roth conversion planning
Roth Lab compares conversion-year tax cost, future RMD tax relief, MAGI and ACA guardrails, IRMAA room, and the projected result versus making no Roth conversions.
What to remember: Roth Lab does not tell you what to do. It helps size the tradeoff, identify possible benefits, and highlight risks worth reviewing before taking action.
Household Retired Now guardrails
Household Retired Now is intended only when everyone in the household is already retired today. It helps compare actual withdrawals, checking-buffer needs, taxable-sale room, annual guardrail room, and Guyton-Klinger style spending adjustments.
What to remember: These guardrails are planning signals. Spending choices remain assumptions unless you create or save a scenario that changes the plan.
Tax assumptions
What is modeled vs. simplified
SimuPlan starts with currently loaded tax tables and threshold assumptions. Officially indexed federal and state values grow into future projection years; future-law risk is tested with Scenario Lab stress inputs rather than predicted as a specific law change.
| Area | Modeled basis | Simplified or beyond scope |
|---|---|---|
| Federal income tax | Loaded 2026 federal tax tables, ordinary income, capital gains/dividends, taxable Social Security, and standard planning deductions. | No return preparation, itemized deduction planning, every credit, every surtax, or forecast of future federal law. |
| State income tax | Reviewed profiles for all 50 states plus DC cover material statewide rules supported by SimuPlan's current inputs, including broad income-tax treatment, retirement-income exclusions, and specialized taxes where relevant. Profiles disclose their model status and source basis. When state law officially indexes a modeled bracket, deduction, or threshold, future projection years grow that value using the plan's inflation assumption. | Rules requiring facts SimuPlan does not collect remain outside the estimate. This includes local taxes, dependent-specific items, itemized deductions, recipient-specific pension eligibility, return elections, transaction-specific adjustments, state-specific edge cases, and future legislative changes. Legally fixed thresholds stay nominal; annually updated rules stay at the loaded value until an enacted update is available. |
| ACA / MAGI | 2026 HHS poverty guidelines, ACA dependents, MAGI room, and projected cap growth from the loaded FPL tables. | Marketplace premium quotes, plan-specific subsidies, and future ACA law changes are not predicted. |
| IRMAA | Roth Lab uses the loaded 2026 first-tier Medicare IRMAA threshold and the selected threshold-growth assumption. | Future CMS thresholds, all surcharge tiers, and household-specific Medicare billing details may differ. |
| Future-law risk | Scenario Lab can stress broad ordinary, capital-gains/dividend, and state tax rates by selected percentage points. | This is a simple rate-increase test. It does not try to guess future tax rules or rebuild the tax code. |
Validation
How SimuPlan is tested
SimuPlan's calculations are tested because users should be able to trust that the model behaves consistently. Testing helps make sure formulas, projections, saved plans, imports, scenarios, and reports continue working as expected when the app changes.
Calculation checks
SimuPlan includes focused tests for the core planning engine: projections, balance tracking, taxes, scenarios, simulations, and supporting calculations. These tests help catch formula changes or data-handling issues before they affect results.
Benchmark comparisons
Some SimuPlan outputs are compared against external calculators, historical datasets, and reference examples. These checks help confirm that results are reasonable and that any differences can be explained. Allocation checks also compare historical return calculations with separate reference calculations. These mathematical checks are distinct from comparisons with another planning tool.
App workflow tests
Automated browser tests open SimuPlan like a user would. They load sample plans, move through pages, edit settings, run workflows, and confirm that important screens render and save correctly. Basic anonymous analytics also help identify which pages and entry points need attention; those events do not include plan values, account names, balances, addresses, login credentials, or saved-plan contents.
Scenario and regression checks
SimuPlan is tested against different plan types, including struggling, middle, and strong plans, as well as Planning for Retirement and Household Retired Now modes. Same-seed randomized comparisons hold the random inputs constant so changes can be distinguished from sampling variation. Legacy allocation and confirmed-mix cases are checked separately.
Interpretation
What SimuPlan is — and is not
SimuPlan is built to help you understand retirement planning choices, compare scenarios, and see which assumptions matter most. Some decisions still deserve review from a planner, CPA, attorney, or Social Security specialist.
- SimuPlan is not designed to guarantee investment results or predict future tax law.
- SimuPlan is not designed to optimize every survivor, estate, beneficiary, or inherited-account strategy.
- SimuPlan is not designed to model every state-specific tax credit, local tax, insurance rule, or household edge case.
- SimuPlan is not designed to replace account statements, brokerage tax forms, or professional advice.
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