Free financial calculators

Money math, answered in real time.

Every calculator updates as you type. Leave any number blank and it’s solved for you: the rate you need, the payment you can afford, the years it takes. No sign-up, and nothing leaves your browser.

Grow your money

Savings, interest and market returns

Compound Interest Calculator

See what savings grow to, or solve for the monthly amount, return or time to reach a goal.

Rule of 72 Calculator

How long until your money doubles, and how accurate the shortcut really is.

Doubling time

S&P 500 Return Calculator

Real historical CAGR for any span since 1871, with dividends and inflation.

Data since 1871

Plan retirement

Early retirement and tax-smart saving

FIRE Calculator

Your financial independence number, years to get there, and how long the money lasts.

Retirement runway

Roth vs. Traditional

Pay tax now or later? Compare after-tax results and find your break-even tax rate.

2026 tax brackets

Borrow smarter

Mortgages, loans and paying off debt

Mortgage & Loan Calculator

Monthly payment, total interest and a full amortization schedule — or solve for rate or term.

Amortization schedule

Debt Snowball vs. Avalanche

Which payoff plan saves more? Or find the payment that makes you debt-free by your goal.

Payoff planner

Value investments

What is a stock actually worth?

DCF Intrinsic Value Calculator

Value a stock from its cash flows, or reverse-engineer the growth its price implies.

Reverse DCF

Live, no Calculate button

Results update on every keystroke, with charts and a plain-English summary.

Solve for any blank

Leave one number empty and it’s solved, using exact formulas or a bisection search that can’t run away.

Private by design

All math runs in your browser. Nothing you type is stored or sent anywhere.

Share any scenario

Your inputs live in the link. Bookmark it, or send it to your partner or advisor.