Fitorex
Calculator

How much to eat, and of what

With a body-fat figure it uses Katch-McArdle, which starts from your lean mass and is more accurate. Without it, Mifflin-St Jeor. That is the same preference the app applies.

JavaScript required

This calculator runs entirely in your browser and needs JavaScript enabled. No data is sent to any server — which is precisely why the maths has to happen here.

Optional. If you know it, the estimate improves.

Other calculators

What this is and is not

These are population equations with a typical individual error of ±10–15%. They are a starting point, not a measurement: what settles it is what happens on the scale, the tape measure and the mirror over two or three weeks. They do not replace advice from a health professional, nor are they suitable for prescribing a therapeutic diet.

Never type it again

In Fitorex these come from your profile and update themselves with every session and every weigh-in.

Free. No account required. Works offline from the first launch.