Not medical advice
Nothing on this site is medical, dietary or clinical advice, and nothing here is a diagnosis, a prescription or a treatment plan. The calculators apply published equations to numbers you type in. They cannot see you, they know nothing about your medical history, and they are not a substitute for a doctor, a registered dietitian or a qualified coach.
If you have a condition affected by diet, exercise or sleep — including heart conditions, diabetes, disordered eating, pregnancy, or any injury — talk to a professional before acting on anything you read here.
Estimates, not measurements
Every figure this site produces is an estimate from a regression equation fitted on a population that is not you. We say so on every page, and we publish the spread between competing formulas precisely so that the uncertainty is visible rather than hidden behind one confident number. Treat the output as a starting point, not a fact about your body.
The one-rep max pages deserve a specific warning: attempting a maximal lift is where a large share of gym injuries happen. The estimate is there so you can programme your training without testing a true max. If you do choose to test one, warm up properly, work up in small jumps, and use a spotter or safety bars set at a height that lets you fail safely.
Use of the site
You may use these calculators freely, for personal or professional purposes, without registering or paying. You may not scrape the site at a rate that degrades it for other people, republish its pages wholesale, or present its output as your own product.
No warranty
The site is provided as it is, without warranty of any kind. We take correctness extremely seriously — every published number is re-derived by an automated test against an independent implementation of the same equation — but we cannot guarantee that every page is free of error, and we accept no liability for any loss or injury arising from use of the site. If you find a wrong number, please tell us.
Links out
Where we link to another site, we do not control what it says or does.
Changes
These terms may change; the date at the top of the page shows when they last did.