Why MiniCalc
exists.

Every calculator site felt dated, spammy, or both. So we built one that isn't.

The idea

A calculator should also teach. Show the formula. Work the example. Explain why the answer is what it is. That way you can spot when a result looks off, and you can use the calculator again without it.

The math, in plain sight

Every engine is plain JavaScript with documented formulas and canonical test vectors. Compound interest matches the textbook $1,000 at 5% monthly for 10 years ≈ $1,647.01. Headline financial calculators match Bankrate and NerdWallet to the penny on standard scenarios. Income tax uses 2026 IRS brackets and all 51 state jurisdictions.

Every calculator's own page lists its formula and sources. If a result looks wrong, it's a bug — tell us.

What we don't do

  • No ads. Nothing pretending to be a button.
  • No accounts. No signups, no email gate, no "log in to see your result."
  • No cookies. Theme preferences live in your browser's localStorage — your device, your bytes.
  • No cross-site tracking. No fingerprinting, no ad networks, no data brokers, no profile that follows you around the web.
  • No selling your data. There isn't any to sell — we never collect anything tied to you.

The one thing we do measure: anonymous visit counts via Cloudflare Web Analytics — cookieless, aggregate-only (pageviews, referrers, country), with no personal data and nothing that follows you across sites. That's it: fonts and the chart library are served from our own domain, so beyond that one beacon your browser makes zero third-party requests. Open DevTools → Network and count them yourself.

When numbers disagree

If MiniCalc gives a different answer than another calculator, it's almost always one of these:

  • Compounding period — daily vs monthly vs continuous.
  • Contribution timing — beginning vs end of period.
  • Rounding — bankers' vs half-up, and at which step.
  • Inclusions — mortgages that include or exclude PMI, taxes, insurance, HOA.

Each calculator's page states the assumptions it makes. If it doesn't, that's a documentation bug.

Get in touch

Found a bug, want a calculator that doesn't exist yet, or just want to say hi? Email hello@… — or use the anonymous "Was this helpful?" buttons on any page.