Learning tool · not advice

One retirement. Thousands of possible futures.

Most retirement calculators hand you one optimistic number. Retirement Scenario Lab runs your scenario through thousands of simulated futures, strong markets, weak markets, a crash in year one, so you can see the whole range, and which choices actually move it. Free, in your browser, no account, nothing to install.

See a sample retiree's odds →

No account · your financial figures never leave your device.

Scenario LabScenario SnapshotScenario Method
THE SCENARIO
Savings today$750,000
Retire at65
Spend / year$70,000
Social Security$30,000
Plan to age92
OUTCOMES, LIVE
Illustrative example — not a real result.
85%
Money lasts (of sims)
$750k
Nest egg at 65
Age 92+
Money lasts to
$410k
Estate (today's $)
Income mix
Guaranteed income 43%
From portfolio 57%
THE MONEY OVER TIME · 1,000 SIMULATIONS
657892
WHERE THE ESTATE COULD LAND
$120k · unlucky$410k · median$820k · lucky

It shows you the math. It never sells you a product or tells you what to do, that part stays yours.

Test any retirement what-if Every formula disclosed & self-checked Private, your numbers stay on your device
Version 1.0 · Updated June 2026 · Runs in any modern browser, nothing to install · Free
A learning tool, not investment, tax, or legal advice, and not a financial planner or advisor.
The question

“Can I actually afford to retire?

You've saved for decades, and still the question sits there. What if you live to 95? What if the market drops 40% the year after you stop working? A single “you're on track” number can't answer that, because retirement doesn't happen on average. It happens once, in one particular sequence of years. That's exactly what this lab lets you test, before you're living it.

How the timing of good and bad markets, not just the average, shapes the result, so you can plan for it.
What a long life, inflation, or care costs would mean, seen ahead of time, calmly, not as a surprise.
How spending, Social Security timing, taxes and account type each move the outcome, made visible.
The strongest levers you control, and the right questions to bring to any conversation about your retirement.
Why it exists

Confidence about your retirement, before you commit

I built Retirement Scenario Lab because the retirement question deserves a better answer than one hopeful number.

No one can predict markets, and no one knows how long they'll live, but you can understand how the pieces move together, and that understanding changes everything.

This is a safe place to explore: retire a year earlier, spend a little less, let a crash land at the worst possible moment, and watch the whole range of outcomes respond. Every formula is disclosed, and the math re-checks itself on every load.

Julie Clarkson, founder · Jacobus Company, LLC

Features

See the whole picture, not a single guess

Change one thing at a time, spending, retirement age, a crash's timing, inflation, taxes, and watch the full range of outcomes respond, with every figure explained in plain language.

🎲

Honest Monte Carlo

Thousands of simulated futures from a market model you control, plus optional replays of real historical crashes — a probability the money lasts and a sampling margin, not a rosy single number.

🌪️

Crisis timing

Slide a real historical crash to any year of retirement and see why when it lands matters, sequence-of-returns risk made clear, so you can plan for it.

📊

Clear visuals

Income-mix ring, success gauge, the money over time, estate range and composition, the trade-offs made obvious.

🏦

Tax & account aware

Pre-tax / Roth / taxable buckets, tax-smart withdrawals, RMDs, and Social Security taxation, the real mechanics.

🧑‍🤝‍🧑

Couples & care

Two lifespans, the survivor transition, and a long-term-care "what if", the real-life factors a single number skips.

📤

Share & export

Share a scenario as a file, export outcomes to CSV, or print a polished PDF report — all part of Pro.

The alternatives

Why not a spreadsheet, or your broker's free calculator?

🏢

Broker calculators

Often one number, and many hand your contact info to a sales team. This runs on your device, sells nothing, and shows the whole distribution.

🧮

Spreadsheets

Spreadsheets average the market. They can't show why a crash in year 1 is a different retirement than the same crash in year 15. The crisis-timing slider can.

💳

$100+/yr planning apps

Many want your accounts linked. Here the full lab is free, Pro is a one-time $14.99 for a year, and the figures you type never leave your device.

Sequence-of-returns risk

Timing matters, see how it plays out

The same downturn lands very differently early in retirement versus later. Slide a real crash (the Depression, the 1970s, 2008, COVID) across your timeline and watch the ending estate respond, so you can see for yourself how much the timing of a crash matters. Every number is clickable for what it means and which input changes it.

CRISIS TIMING · WHEN THE CRASH LANDS
Crash in year 1
Runs dry ~86
Crash in year 8
Lasts to 92
Crash in year 15
$540k left
Illustrative: the same crash, three different retirement years.
EVERY OUTCOME EXPLAINED
Money lasted in 85% of simulated futures
The share of thousands of simulated futures where the money never runs out — an illustration of your assumptions, not a prediction or a promise. Tap any number for what it means, how it's figured, and a link to the input that moves it.
Nothing hidden

Every number is explained, and verifiable

Each figure traces to a plain-language explanation on the Method page, and a live self-check suite (currently 30 checks) runs in your browser on every load. Historical stock and inflation figures are drawn from public records and spot-checked; bond totals are a close approximation. No black box, no "trust us." This tool is independent and not affiliated with, sponsored by, or endorsed by any index provider.

Helpful at every stage

For wherever you are

Whether retirement is decades away or right around the corner, it's a place to pressure-test the scenario before you commit.

🌱

Years to go

See how saving, retiring a bit later, and market ups-and-downs shape whether the money will last.

🎯

Near retirement

Stress-test the number, test Social Security timing and flexible spending, and pressure-check bad-market timing.

🤝

Financial advisors

Have clients explore scenarios before the meeting, so they arrive informed and ask the right questions.

How it works

Simple to use. Honest under the hood.

1

Describe a scenario

Age, savings, spending, Social Security, and a plan-to age, round, hypothetical numbers are perfect. No personal details.

2

Test the world

Add taxes, care costs, a couple, flexible spending, and a real crash at any point, watch the odds move live.

3

See the range

The probability the money lasts, the year-by-year path, the estate range, and what drives each number.

4

Learn the levers

Finish knowing which choices move the outcome and the right questions to bring to a professional. It's a learning tool, not advice, so the decisions stay yours.

Pricing

Start free. Upgrade when you need more.

The full simulator, Monte Carlo, crash testing, every chart, is free forever. Pro is for when one scenario isn't enough and you want to line your what-ifs up side by side.

Free

$0
Everything you need to explore and learn.
  • Full Scenario Lab, Monte Carlo & charts
  • 1 saved scenario
  • Runs locally, private, no account
Open it free →
PRO

Pro

$14.99 one year
For comparing many what-ifs side by side.
  • Everything in Free
  • Unlimited saved scenarios & compare
  • Unlimited sharing
  • Print report (PDF)
  • Export outcomes (CSV)
  • Import a scenario
  • Backup & restore
  • Every update for your license year
Get Pro
one-time $14.99 for a year · up to 5 device activations · no refunds

One-time $14.99 for a full year of Pro, it does not auto-renew. One license covers up to 5 device activations. No refunds.

Good to know

How it handles your data

The financial figures you enter never leave your device — they're computed in your browser. The only things ever sent are a Pro license key to verify a purchase, and your email if you opt in — never your scenario figures. Because it's an open page rather than a locked vault, work in round numbers and skip names and account IDs; ballpark figures are all the math needs anyway.

🙅

No account for the free tool

Just open it and explore. You only provide an email if you choose to get updates or subscribe to Pro.

💾

We don't save your scenarios

The numbers you type stay in your own browser on your device, we never receive or store them. To keep one, export it; clearing your browser erases it.

📖

You can read the code

It runs in your browser, so you can open View Source and see exactly what it does.

Versions

Always on the latest version

It runs in your browser, so everyone is automatically on the newest release, nothing to download or update.

LATEST
Version 1.0
Released June 2026 · Web app, auto-updates, nothing to install
Open it →
WHAT'S NEW IN 1.0
  • Monte Carlo with optional real historical crash replays
  • Crisis-timing slider (sequence-of-returns risk)
  • Account-type taxes, RMDs & Social Security
  • Couples, survivor & long-term-care modeling
  • Visual Scenario Snapshot & printable PDF report (Pro)
  • Free: 1 saved scenario · Pro: unlimited saves, sharing, export, print, import & backup
Also from us: Investment Scenario Lab
A sibling learning tool for exploring investment scenarios and mixes before you invest.
Visit Investment Scenario Lab →
FAQ

Frequently asked questions

Is this financial advice?

No. It's an educational illustration tool that runs math on the assumptions you provide, and it never recommends a specific product or strategy. Use it to understand trade-offs, then consult a licensed fiduciary and a CPA before acting.

Where does my data go?

Your financial figures never leave your device — they're computed in your browser and live in its local storage. The only things ever sent are a Pro license key to verify a purchase and your email if you opt in — never your scenario figures. Export a scenario to keep it, or clear your browser data to erase it. Because it's an open page rather than a locked vault, work in round numbers and skip names and account IDs; ballpark figures are all the math needs anyway.

How accurate are the projections?

The math is standard and transparent, and the market history is the 1928–2023 record (stocks and inflation verified against the public record; bond totals closely approximated); accuracy depends on the assumptions, which are dated and adjustable. It maps a range of plausible futures, it's not a prediction.

Do I need to install anything?

No. It's a web page: open the link and you're in. It works in any modern browser on any operating system, with no account.

What do I get with Pro?

Unlimited saved scenarios so you can compare many what-ifs side by side, plus unlimited sharing, print report (PDF), export outcomes (CSV), import a scenario, and backup and restore, with every update during your license year. Pro is a one-time $14.99 for a full year and does not auto-renew. One license covers up to 5 device activations, and is non-refundable.

How is this different from FIRECalc or my broker's calculator?

Three ways: it models the mechanics most free calculators skip (account-type taxes, RMDs, Social Security taxation, couples and the survivor transition, long-term care); it shows the full range of outcomes instead of one number; and it's private, no account, no lead-gen, your figures never leave your browser.

Who's behind this?

Retirement Scenario Lab is built by Julie Clarkson under Jacobus Company, LLC (North Carolina, USA). Questions: scenario-labs@julieclarkson.com.

Notify me about updates.

Get new features, practical tips, and early access. 1-2 emails a month for this product and other products from Julie Clarkson.

Meet your thousand futures before you pick one.

Run the what-ifs tonight, free, no account, and walk into your next conversation (with your spouse, or a fiduciary) already knowing which levers matter.

Open the tool, free → See Pro
Free to start · Pro available · Private by design