Two people can weigh the same and need very different amounts of food. Muscle burns more than fat, so this calculator works from your lean body mass: everything you weigh that isn't fat. Don't know your body fat? Grab a tape measure and estimate it right here.
Your lean body mass
0 kg
Fat tissue needs very little energy to keep alive. Muscle, organs and bone need much more. So a formula based on total weight overestimates calories and protein for people with more body fat, and underestimates them for lean, muscular people.
This calculator uses the Katch–McArdle equation, which only looks at your lean mass, then sets protein from that same lean number. Fat is set at 25% of calories, and carbs fill in the rest.
| Category | Men | Women |
|---|---|---|
| Essential fat | 2–5% | 10–13% |
| Athletes | 6–13% | 14–20% |
| Fit | 14–17% | 21–24% |
| Average | 18–24% | 25–31% |
| Above average | 25% and up | 32% and up |
Ranges from the American Council on Exercise. The tape method uses the US Navy body fat formula, which is usually within 3–4% of lab tests.
It's everything in your body that isn't fat: muscle, bone, organs, skin and water. If you weigh 80 kg with 20% body fat, your lean body mass is 64 kg.
DEXA scans are the most accurate. Smart scales and calipers are rough guides. The tape method on this page, from the US Navy, is free and usually close enough for setting macros.
Around 2 to 2.5 grams per kg of lean mass suits most people trying to lose fat or build muscle. That's about 1 gram per pound of lean mass.
It can be, as long as your body fat estimate is decent. It's especially useful for very lean, very muscular or higher body fat people, where weight-only formulas drift the most.
Yes. Strength training plus enough protein builds muscle, which raises lean mass. Beginners often gain lean mass even while losing fat.
Want to see your BMR with three formulas side by side? Try the TDEE calculator.
Open the TDEE calculator