About TheCalcUniverse
TheCalcUniverse is a free reference site: 343 calculators across 10 categories, each one built to show its work — the formula, a worked example, and the limitations — not just spit out a number.
343
calculators
168
in-depth guides
7,173
automated tests
How the calculators are built
Every calculator is a small, tested program with a documented formula. Where a formula has an academic or regulatory source (loan amortization, BMI cutoffs, GFR equations), the source is cited on the page. Money math runs on precise decimal arithmetic, not floating-point shortcuts. See how we build and verify calculators for the full standards.
What we don't do
No accounts, no paywalls, no selling data. Your inputs never leave your browser — every calculation runs locally on your device. The site is a set of static pages served from a CDN, which is also why it's fast.
Something wrong?
If a formula, definition, or result looks off, tell us: contact@thecalcuniverse.com. Corrections ship quickly — the whole site rebuilds in under a minute.