Free · no sign-up · your numbers stay in your browser
Know if your money will last.
Two tools, one question. Estimate how an investment grows in two minutes, or stress-test a full retirement plan against 1,000 simulated market histories.
Quick estimate
~2 min
Simple Investment Calculator
See how an investment grows. Starting amount, contributions, and a return rate in — end balance, growth chart, and a year-by-year schedule out.
- Compound growth with monthly or annual contributions
- Breakdown of what you put in vs. what it earned
- Full accumulation schedule
Full plan
~10 min
Advanced Simulation
Stress-test a retirement plan: 1,000 Monte Carlo trials with taxes and account types, Social Security, guardrails spending, and historical crash replays.
- Probability your money lasts, with best/worst-case ranges
- Taxable, tax-deferred, and Roth accounts with RMDs
- Stress tests: stagflation, dot-com, 2008, 2022
Not sure which? Start simple. If the question is “what will my savings be worth,” the calculator answers it. If it is “can I actually retire on this,” the simulation does — and it explains every input with a tooltip as you go.