About Calcelate

Calculators that show their work.

Calcelate is a collection of free calculators for money, health, home, pets and everyday life. Each one gives the number first, then shows the formula behind it, a worked example, and the sources the formula comes from. The maths runs in your browser and your inputs are never stored with anything that identifies you; see the privacy page for the analytics we use.

Why show the work

A number on its own is easy to get and hard to trust. Most calculators online hide how they arrive at a result, so two of them will disagree and you have no way to tell which is right. We publish the formula, name the source, and date every check, so you can see whether the assumptions match your situation and correct them if they do not.

Who makes it

Calcelate is built and maintained by the Calcelate Team, a small independent group. We are not doctors, lawyers or financial advisers, and the site is not a substitute for one. Where a calculator touches health or safety it says so plainly and points you to the right person to call.

What is here today

43 calculators across 7 sections: Finance, Health, Everyday, Pets & livestock, Construction, Marketing, Generators. New ones are added in waves; each is tested before it goes live. See how we calculate for the process.

Found a mistake?

Tell us. A wrong formula or a stale number is the worst thing this site can have, and a report from a reader is the fastest way to fix it. See report an error.