S&P 500 Backtest Simulator
→"What if I'd invested back then?" Run any window through real annual total returns — dividends, inflation, CAGR, and max drawdown, all on a live chart.
Plan Your FIRE
FIRE Number Calculator
→The portfolio size you need to retire early — and your years to freedom.
Coast FIRE Calculator
→See if you can stop saving and let compounding finish the job.
Lean FIRE vs Fat FIRE
→Compare both targets and the years to reach each.
4% Rule Calculator
→How much you can safely withdraw, and how long your money lasts.
Grow & Invest
Compound Interest Calculator
→Project how an initial amount plus monthly contributions grows over time.
S&P 500 Backtest
→Test historical outcomes with real total returns since 1928.
Crush Debt
Debt Payoff Calculator
→Avalanche vs snowball — which clears your debt faster and cheaper.
Early Mortgage Payoff
→See the interest and years you save with extra monthly payments.
New tools are added regularly. Every calculator is free, runs entirely in your browser, and never asks for your email. For educational purposes only — not financial advice.