This site is a growing collection of free online tools: calculators, unit converters, text and developer utilities and generators. They open instantly, need no sign-up and work on a phone as well as on a computer.
How the tools are built
- They run in your browser. What you type is processed on your device. Nothing is uploaded, so you can use the tools with private data.
- Every formula is written down. Each page explains the method and shows a worked example, so you can check a result by hand.
- Results are tested. Every calculator has control examples with hand-checked answers that run automatically before each release.
- In your language. Every page is adapted to its language, with local number formats, units and examples.
Limits
The tools give general information. Health calculators do not replace a doctor, and finance calculators do not replace a financial adviser.