About Zulu Calculator

Zulu Calculator is a growing collection of free calculators for pilots, travellers and everyday numbers. Every tool updates as you type, explains the formula it uses and works without an account.

How we build calculators

Each calculator shows its formula and a worked example, so you can check the answer yourself. Unit factors and reference values are taken from published standards and noted on the page.

Why "Zulu"?

In aviation, Zulu is the name for Coordinated Universal Time, the single clock pilots around the world plan by. We liked the idea of one dependable reference for numbers too.

Spotted a mistake?

Accuracy matters to us. If a result looks wrong, please tell us and we will check it.