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Monte Carlo retirement calculator
Find the number you actually need, at the confidence you choose, then the one change that closes the gap. Five short steps, 1,000 simulated futures, and a straight answer in plain words.
About ten minutes. You can change every number later.
What you leave with
Your number
One figure at 80% or 90% confidence, built from 1,000 simulated futures, not a single smooth line.
The gap
What you have, what you are projected to have, and the distance between that and the target.
The one move
Save more, retire later, or trim. One change, with the smallest ask first, so it is easy to act on.
The five steps
Questions you can answer without a spreadsheet.
Every step ships with a workable default, so you see a full answer before you type anything. Change one number and the answer moves with you.
Step 1
What you spend
A rounded monthly figure. It shapes the answer more than anything else.
Step 2
What you own and owe
Savings, investments, retirement accounts, and the debts against them.
Step 3
What arrives in retirement
Social Security, pensions, and any guaranteed income.
Step 4
When you stop working
Your age today, and the age you would like to pause.
Why Monte Carlo
One smooth line hides the thing that decides the outcome.
A plan can look fine on average and still fail if the bad years arrive first. We run your plan 1,000 times, each with a different market every year and a different lifespan. The answer is the number that works in 80 or 90 of 100 futures.
1,000
simulated futures
80% or 90%
confidence you choose
1
change that closes the gap
Common questions
Straight answers before you start.
How much do I need to retire?
It depends on what you spend, when you stop working, and what arrives in retirement. The calculator turns those into one number at a confidence you choose, then shows the gap between that number and where you are today.
What is a Monte Carlo retirement calculator?
A normal calculator projects one smooth line to a fixed age. A Monte Carlo calculator runs your plan many times, with a different market every year and a different lifespan, and counts how often the money lasts. We run it 1,000 times.
Is it free?
Yes. There is no account and no paywall. Your plan stays in your browser and never leaves the device.
What confidence level should I choose?
80% is a realistic plan. 90% is a fortress that survives severe recessions. Higher confidence costs more, either in savings or in years worked. You pick how safe you want to be.
Does it work outside the United States?
The simulation is general. The tax, Social Security, and retirement account rules are US. Use the spending, asset, and age steps anywhere, and treat the benefit and tax figures as a US layer.
Ready to see your number?
Free, private, and about ten minutes.