About

Who makes this, and what

This is the hub for a small group of independently run sites that publish free calculators and tools. Each tool lives in its own section of this site (for example /energy/); the home page describes each site that is open now, and the other pages here state our publishing principles.

Why we make it

Many calculators online do not say what data or rules they use. We state the method, the data source and the reference date, and we write guides that explain how to read the result and where it stops being reliable.

Ads or affiliate links may appear, but they never change a result or an explanation.

What we do not do

We do not run services that require sign-up or login, that store what you type, or that make investment, tax, legal or medical decisions for you.

Operator

Clewbox (independently run)