About InfiniteCalc

InfiniteCalc exists for one reason: to give you the right answer, fast. We build free online calculators for finance, health, math, dates, unit conversions, and everyday life — 103+ tools and growing every week.

Every calculator on this site is built on established, verifiable formulas — the amortization formula lenders actually use, the Mifflin-St Jeor equation dietitians rely on, the U.S. Navy body fat method, and so on. Each tool explains its formula and shows worked examples, so you can understand the result, not just read it.

All calculations run instantly in your browser. We never ask you to sign up, and we never store what you type.

How we build and verify calculators

We don't invent math — we implement the established, citable formula for each problem and name it on the page:

Finance — the standard amortization and compound-interest formulas lenders and banks actually use, including APY computed as (1 + r/n)ⁿ − 1.
Health & fitness — peer-reviewed equations: the Mifflin-St Jeor equation for BMR and calories (American Journal of Clinical Nutrition, 1990), the U.S. Navy circumference method for body fat (Naval Health Research Center), and the Epley and Brzycki formulas for one-rep max estimates.
Math & conversions — standard order of operations (PEMDAS), the exact conversion factors fixed by international agreement (1 inch = 25.4 mm exactly), and textbook statistical definitions, stated on each page.

Before a calculator goes live, its results are cross-checked against an independent implementation of the same math — not just eyeballed — and tested against edge cases: invalid inputs, extreme values, boundary conditions, and unit-conversion round trips. Our scientific calculator alone shipped after passing a suite of more than a hundred verification tests. The article content around each tool is checked against the same math, so the worked examples you read match the results the calculator produces.

When a formula produces an estimate rather than an exact answer — growth projections, health metrics, score predictors — the page says so plainly. And if you ever find a result you believe is wrong, email us: reported errors are treated as our highest-priority fixes, because accuracy is the entire point of this site.

Embed our calculators

Every calculator on this site can be embedded on your own website or blog for free — look for the “Embed this calculator” button under any tool. Teachers, bloggers, and businesses use them to give their visitors working tools without building anything.

Accuracy Disclaimer

Our calculators are provided for informational and educational purposes. Results are estimates and do not constitute financial, medical, tax, or legal advice. Always consult a qualified professional before making important decisions.

Contact

Found an error, have a question, or need a calculator we don't have yet? Email us at [email protected]. We read every message and typically reply within a day.