About Calc-Tool

Calc-Tool is a free collection of 21 calculators for finance, health, and everyday questions. Every tool runs instantly in your browser — there is nothing to install and no account to create.

Our principles

Accuracy first. Each calculator uses a documented, standard formula, and the math is covered by an automated test suite so results stay correct as the site grows.

Fast and private. Calculations happen entirely on your device. We do not send your inputs to a server.

Free forever. The site is supported by unobtrusive advertising so the tools can stay free for everyone.

A note on advice

Our calculators are for general information and education. They are not a substitute for professional financial, medical, or legal advice. Always consult a qualified professional before making important decisions.