MoneyMath

The math of money,
made simple.

Free calculators for FIRE, savings, net worth, and the real cost of the things you spend on. Run privately in your browser. No accounts, no tracking — just honest math, plainly explained.

0 bytes sent to a server 15 calculators ~30s to a real answer

FIRE family

When can you stop working?

Four flavors of financial independence. Same math, different lifestyle bets.

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Income & Wealth

What you make. What you keep.

The earning side of the balance sheet — your real hourly rate, what to charge clients, and the single number that captures your whole financial picture.

Debt & Costs

What things actually cost.

Money flowing out — over the full life of the loan, the car, the education. Sticker price is the smaller half of the answer.

One short note a week.

A new calculator, a back-of-the-envelope tear-down of a money decision, or a reading list. No fluff.

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