Finance Calculators

Make better money decisions

Borrowing and saving decisions are made once but felt for years. A mortgage rate half a point lower, a car loan two years shorter, or starting retirement contributions five years earlier can each be worth tens of thousands of dollars. These calculators show the full cost or benefit — not just the monthly number — so you can compare options side by side.

All calculations run in your browser; nothing you enter is sent to us or stored. Results are estimates based on the figures you provide and are not financial advice.

Which finance calculator do you need?

• Buying a home: start with house affordability to set a budget, then use the mortgage calculator for the full monthly payment and mortgage points to decide whether paying for a lower rate is worth it. Lenders will check your debt-to-income ratio.
• Borrowing: the loan calculator covers personal and student loans with an amortization schedule; the auto loan calculator adds sales tax, trade-ins and fees; the credit card payoff calculator shows how long a balance will take to clear.
• Saving: plan a target with the savings goal, emergency fund and sinking fund calculators; compare accounts with the APY calculator.
• Investing and retirement: see long-term growth with compound interest and the retirement calculator; measure results with ROI, CAGR and the stock average calculator; plan early retirement with FIRE number and Coast FIRE.
• Rental property: compare deals with cap rate and cash-on-cash return; split partial months with prorated rent.
• Pay and work: convert pay with salary to hourly, and check a raise, overtime pay or a freelance rate.

Five ideas behind almost every money decision

1. Compounding works both ways. Interest earned on interest grows savings; interest charged on unpaid interest grows debt. The longer the time, the bigger the effect — see the Rule of 72 for a quick estimate.
2. APR and APY are different. Loans quote APR; savings quote APY, which includes compounding. Compare like with like.
3. Lower payments often cost more. Longer loan terms reduce the monthly payment but increase total interest.
4. Inflation shrinks money. At 3% a year, prices double in about 24 years. Plan long-term goals in today’s dollars with the inflation calculator.
5. Fees and taxes matter. A 1% annual fee or an untaxed vs. taxed account can change a 30-year result by a quarter or more.

How we keep these calculators accurate

Each calculator uses the standard formula for its purpose — for example the amortization formula used by lenders, the 28/36 debt-to-income guidelines used in mortgage underwriting and the U.S. federal overtime rules — and names it on the page. Every formula is checked by automated tests against worked examples before publishing. Tax rates, wage bases and limits that change yearly are reviewed regularly. If you spot an error, please let us know.