Most retirement calculators ask three questions and spit out a number. Ours does the work an actual financial planner would do — modeling sequence-of-returns risk, life events that shift your trajectory, how your withdrawal approach plays out (a fixed inflation-adjusted amount or a percent of your balance each year), and the effect of Social Security claim timing.
You enter your current age, balances, savings rate, and target retirement age. We run a Monte Carlo simulation across 1,000 randomized market paths and tell you the probability your money outlasts you under the withdrawal approach you choose. Add a child's college payment, a paid-off mortgage, an inheritance, a career break — every life event flows through the projection.
When the answer changes — and it will — adjust the inputs and see the new probability immediately. Save scenarios, compare them side-by-side, and share the plan with your spouse or advisor.
What you can do
- Monte Carlo simulation across 1,000 randomized market paths
- Sequence-of-returns risk modeling, not just average returns
- Life events: college payments, inheritances, career breaks
- Withdrawal modeling: percent-of-balance (the 4% rule) or fixed inflation-adjusted dollars
- Social Security claim-age comparison
- Save and compare unlimited scenarios
- Share scenario links with anyone
Frequently asked questions
How is this different from a basic retirement calculator?
Basic calculators assume an average annual return and project a straight line. Real markets move in waves, and the order of returns matters enormously when you're drawing down. Our calculator runs Monte Carlo simulations to surface that sequence-of-returns risk and gives you a probability of success rather than a single number.
Do I need to create an account?
No. The calculator works without signing in. If you want to save scenarios or share them, sign-in is free with Google or email.
What withdrawal approaches do you support?
Two withdrawal modes: a percent of your balance each year — set it to 4% for the classic "4% rule" — or a fixed monthly amount that grows with inflation. Save a scenario in each mode to compare them side-by-side.
Can I model early retirement or financial independence?
Yes — the Financial Independence Planner focuses on the early-retirement question directly: if you retire at a chosen age with a chosen monthly spending level, how long does the money last?
Which retirement assumptions change the answer the most?
Retirement age, annual spending, Social Security timing, investment return, inflation, taxes, and life expectancy usually move the result the most. If one assumption is uncertain, run a conservative and optimistic version instead of trusting one middle number.
Ready to run the numbers?
The Retirement Calculator runs entirely in your browser. Free, no sign-up required to use it.
Related articles
Practical examples that connect the calculator to real planning decisions.
Can I Retire at 62 and Delay Social Security Until 70?
Retiring at 62 while delaying Social Security until 70 can work, but the eight bridge years decide the plan. See one calculator scenario and the key levers.
The 4% Rule in 2026: Morningstar Says 3.7%, Bengen Now Says 4.7% - Which One Applies to You?
Morningstar says 3.7%, Bengen says 4.7%, and the classic rule says 4.0%. See one retirement calculator scenario tested across all three rates.
Is the 4% Rule Still Safe in 2026? A Visual Stress Test
Use charts to see how the 4% rule works as a starting withdrawal test, why flexible spending changes the result, and when Monte Carlo stress testing matters.
Related calculators
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