Free financial calculators that
show their math.
Every tool shows its formula and works through an example. No sign-up, no email wall, no black box.
FLAGSHIP CALCULATOR
Coast FIRE Calculator
How much do you need saved today so compounding alone funds your retirement? Get your number in about 30 seconds.
Browse by goal
FIRE & Early Retirement
Coast FIRE, FIRE number, Barista FIRE + 3 more — 6 calculators
Get Out of Debt
Snowball vs avalanche, debt payoff, credit cards — 4 calculators
Paycheck & Taxes
Take-home pay in all 10 states — gross-to-net calculator
DTI & Mortgage
Check your debt-to-income ratio before you apply — 1 calculator
Guides
Plain-English explainers behind every formula — 14 guides
All calculators
Every retirement, debt, and tax calculator — 22 interactive tools