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, the difference between safe-withdrawal-rate strategies, 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 each strategy you want to compare. 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 strategies: 4% rule, guardrails, dynamic spending
- 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 strategies do you support?
The classic 4% rule, Guyton-Klinger guardrails, dynamic spending tied to portfolio performance, and a fixed-real-dollar strategy. You can compare any two 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?
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.
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
Other tools that pair well with the Retirement Calculator. They cross suites because life does.