Financial Calculators
Mortgages, loans, investments, retirement, taxes and currency conversion — the math you need to make better money decisions, free and accurate.
Make Money Decisions with Real Numbers
Personal finance is mostly arithmetic, but the arithmetic compounds — small assumptions, repeated over decades, become large outcomes. A 7% return versus a 6% return on a 30-year retirement portfolio is the difference between a comfortable retirement and a tight one. A 30-year mortgage versus a 15-year mortgage at the same rate is hundreds of thousands of dollars in lifetime interest. The financial calculators in this section let you test those assumptions before you commit real money to them.
What You Can Calculate Here
The mortgage calculator shows your full monthly payment including taxes, insurance and PMI, plus a year-by-year amortization schedule. The loan calculator works for any fixed-rate loan — student, personal, business. The auto loan calculator handles trade-in value, sales tax and fees. Compound interest and investment return calculators show the long-run power of regular contributions. The retirement / FIRE calculator projects your nest egg and the financial-independence number you're aiming for. Tax and salary tools — income tax, sales tax, salary — let you sanity-check pay stubs and receipts. The currency converter uses live exchange rates for travel and international purchases.
Multi-Currency Display
Every dollar-denominated calculator on this site includes a currency selector at the top: USD, EUR, GBP, CHF, JPY, CAD, AUD and INR. The selector changes only the display formatting, not the math — a $10,000 deposit at 5% grows to the same number regardless of whether we show it with a $, €, £ or ¥ symbol. For actual currency conversion between two currencies (e.g., "how many euros is $100 right now"), use the dedicated currency converter which fetches live rates.
About Our Math
These calculators use the standard formulas you'd find in any finance textbook: the amortization formula for mortgages and loans, future-value-of-an-annuity for investment growth, and so on. We compound monthly by default because that matches how most U.S. financial products actually work. Inputs are stored locally in your browser so your scenario sticks around between visits — nothing is transmitted to a server.