Lean Body Mass Calculator

Two reasons. First, protein needs scale with lean mass, not total weight. A 200 lb person at 30 percent body fat needs less protein than a 200 lb person at 12 percent. Second, LBM is the part of you that lifting builds. Tracking LBM over months tells you whether your training is actually adding muscle.

They are complements. Body weight equals lean body mass plus fat mass. If you weigh 180 lb and your LBM is 144 lb, your fat mass is 36 lb, which is 20 percent body fat. Knowing one gives you the other.

Each was fit on a different study population. Boer (1984) is the most cited modern formula and is our default. James (1976) is more conservative for very heavy individuals. Hume (1966) was the original regression from cadaver data and is still used in pharmacology dosing.

These formulas use only height, weight, and sex, so they cannot account for individual body composition. Expect a 5 to 10 percent error at the individual level. For more accurate LBM, measure your body fat with skinfolds or DEXA and compute LBM as weight times (1 minus body fat percent).

For resistance trainees, around 2.0 to 2.7 g per kg of LBM per day. That is the ISSN 2017 position-stand range translated from total-weight to LBM-based at typical body fat. We show your target below.