Body Recomposition Target Calculator
Turn a goal body-fat percentage into a target scale weight that keeps your lean mass, so you can plan a recomp instead of just cutting.
How it works
Lean mass = weight × (1 − BF%) · Target weight = lean mass ÷ (1 − goal BF%) · Fat to lose = current fat − target fat
Body recomposition means changing your ratio of fat to muscle rather than just watching a single scale number fall. The key insight is that lean body mass is the part you want to protect, so the target weight is computed by holding lean mass constant and asking what total weight would put your desired body-fat percentage on top of it. If you also add muscle during the process, your true target weight will be a little higher than this — the tool assumes lean mass stays fixed, which is the conservative planning case.
Worked example
At 175 lb and 24% body fat, lean mass is 175 × 0.76 = 133 lb and current fat is 42 lb. To reach 18% body fat while keeping that lean mass, target weight is 133 ÷ 0.82 = 162.2 lb, of which 29.2 lb is fat — so the plan is to shed about 12.8 lb of fat, not muscle.
Frequently asked questions
Why not just pick a goal weight directly?
A goal weight alone ignores composition. Two people at the same weight can look and perform very differently depending on how much of that weight is muscle. Anchoring the goal to a body-fat percentage keeps your hard-won lean mass in the plan.
Can I gain muscle and lose fat at the same time?
It is possible, especially for beginners, people returning after a break, or those with higher body fat. In that case your real target weight sits above this estimate because lean mass is rising. This tool models the simpler case of preserving current lean mass.
How accurate does my body-fat number need to be?
Consistency matters more than precision. Home scales and calipers can be off by several points, so use the same method over time and watch the trend rather than any single reading.
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Educational estimate only — not medical advice, diagnosis, or treatment. Individual needs vary; consult a qualified healthcare professional for decisions about sleep, hydration, nutrition, exercise, or ergonomics.