Body composition · Step 1

Body Fat Percentage Calculator

Estimate body fat, understand the range and use it alongside training experience to choose your next step.

Choose your method

Use body-fat estimates as one part of the picture

Recomposition means losing fat and gaining muscle over the same period. Weight may fall, stay similar or rise, depending on the balance of those changes. Track waist, body measurements and training performance alongside the weight trend; none is conclusive on its own.

BMI tracks weight relative to height, not fat and muscle separately. During recomposition, BMI may fall, stay similar or rise. Even when it changes, it cannot tell you which tissue changed. Compare it with body measurements and training progress.

A falling body-fat percentage can reflect changes in fat, lean mass or both. It does not establish muscle gain on its own. Compare estimates made with the same method and conditions alongside weight, waist and training progress.

What your body fat % implies for the recomposition protocol

ACE sex-specific bands paired with the two inputs that scale with body fat %: realistic fat-loss pace (during a cut) and protein target. Body recomposition is not one path; this is the deficit-and-lifting version. Sources below.

BandMenWomenCut pace · % BW / wkProtein · g/kg BW
Essential
Men2–5%
Women10–13%
Cut pacenot advised
Proteinn/a
Below the physiological floor. Sustained energy deficits at this level trigger RED-S: hormonal, immune, and bone consequences.
Athlete
Men6–13%
Women14–20%
Cut pace≤ 0.5%
Protein2.0–2.8
Visible muscularity. Protein needs climb because lean mass is harder to defend the leaner you go.
Fitness
Men14–17%
Women21–24%
Cut pace0.5–0.7%
Protein1.8–2.4
Recomposition keeps working through small deficits or maintenance.
Average
Men18–24%
Women25–31%
Cut pace0.7–1.0%
Protein1.6–2.2
The largest weekly weight change is tolerated here without disproportionate lean loss.
Above average
Men≥ 25%
Women≥ 32%
Cut pace1.0–1.5%
Protein1.6–2.0
Cardiometabolic load climbs from here. Aggressive deficits are best tolerated at this band.

Sources: Helms 2014 (protein during deficit, scaled by leanness) · Garthe 2011 (fast vs slow cuts on lean retention) · Longland 2016 (high protein + deficit + lifting drives recomposition) · Mountjoy 2014 (RED-S risk below the essential floor) · Barakat 2020 (recomposition is also possible at maintenance or in a small surplus for novices and detrained lifters).

Picking a method you can repeat

Tape measurements, skinfolds and visual comparisons estimate body fat with different sources of error. Use a method you can repeat under similar conditions. Small changes may reflect measurement error; use the trend alongside other progress signals.

A falling body-fat percentage can reflect changes in fat, lean mass or both. It does not establish muscle gain on its own. Compare estimates made with the same method and conditions alongside weight, waist and training progress.

Body recomposition, asked and answered

Six questions people search when their body fat % stops moving.

Recompose with Recomp AI

Use body-fat estimates as one part of the picture

Recomp AI brings your food log, weight trend and body measurements together. Review them alongside your training progress to decide whether your calorie target needs adjusting. Stable weight alone does not show whether you lost fat or gained muscle.

References