Guides
The background behind the calculators: what the numbers mean, where the methods came from, and how to get a clean input.
- Body fat percentage ranges: what the numbers can and cannot tell youPublished body fat percentage ranges explained: the ACE categories, how age, sex and measurement method shift them, and why one number says little.
- Navy vs Army body fat methods: what is differentCompare the US Navy and Army tape methods: what each measures, how the formulas differ, why the Army dropped its tape test in 2026, and what that means.
- How to test your one-rep max safely (or estimate it instead)A practical guide to finding your 1RM: when to estimate from a rep set, how to run a direct test with a spotter, warm-up steps, and when to skip it.