You’re in a shop, and the sign says 30% off. You’re splitting a dinner bill six ways. You’re wondering how many days are left until the holiday, or what a loan will really cost each month. So you search, click the first calculator, and wait. The page jumps as the ads load. A cookie banner covers the input. A video starts playing somewhere. Eventually you find the answer, probably.
We thought that was a strange way to treat a sum. So we made the opposite.
What you get
- The calculator first, at the top of the page, on any screen.
- Results that update as you type. No “calculate” button, no waiting.
- The formula, in plain words and as math, with a worked example — so you can check our work.
- A link that brings back exactly what you typed, for sharing or bookmarking.
- No accounts, no pop-ups, no tracking cookies, and no ads.
Why 99%?
Because 100% would be a lie. Right now there are 233 calculators here, covering percentages, money, dates, health, home projects, conversions and the school math that keeps showing up in real life. That handles most of the everyday questions people actually ask. Not all of them.
The missing 1% is where you come in. If you needed something we don’t do, or you think a result is wrong, report a 1% problem. We read every one, and the good ones become new calculators.
How we keep it right
Every calculator uses a standard, textbook formula, and every one of them is checked by automated tests against known correct answers — including awkward cases like zero, negative numbers, leap years and very large values. Where a result is only an estimate (health, cooking conversions, DIY quantities), we say so on the page. Where a question really needs a professional, we say that too.
Think of us as the friend who’s good at math. Helpful first. Occasionally funny. Never smug about it.