About MyBMI Tools

MyBMI Tools is a free collection of everyday calculators for money, health, maths, weather, science, home projects and day-to-day tasks.

What this site is for

The goal is simple: give you a clear answer quickly, and show the working behind it. Each calculator is designed to explain the formula it uses, walk through a worked example, and list the assumptions or limits that matter, so you can check the result rather than taking it on faith.

What you will find here

• 62 calculators across seven categories: financial, fitness and health, maths, weather and environment, chemistry and science, construction and home, and other everyday tools.
• Plain explanations on every calculator page — how to use it, how the calculation works, the formula, a worked example and the assumptions.
• Helpful extras such as copy, print, CSV export, share links, favourites and saved history, so you can keep or reuse a result.

How it works

All calculations run in your web browser. There is no account to create and no sign-up. You can read more about how data is handled on the Privacy page and more about the maths on the Methodology page.

A note on accuracy

Every tool shows its formula and assumptions so you can judge whether it fits your situation. Results are rounded for display where that makes sense, but the underlying calculation keeps full precision. For important decisions, treat the result as an estimate and double-check the inputs and the assumptions.