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.
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.
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
- Murphy C, Koehler K. Energy deficiency impairs resistance training gains in lean mass but not strength: A meta-analysis and meta-regression. Scand J Med Sci Sports, 2022;32(1):125-137.
- Antonio J, Ellerbroek A, et al. A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women: a follow-up investigation. J Int Soc Sports Nutr, 2015;12:39.
- Longland TM, Oikawa SY, et al. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss. Am J Clin Nutr, 2016.
- Garthe I, Raastad T, et al. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. Int J Sport Nutr Exerc Metab, 2011.
- Mountjoy M, Sundgot-Borgen J, et al. The IOC consensus statement: beyond the female athlete triad, relative energy deficiency in sport (RED-S). Br J Sports Med, 2014.
- Barakat C, Pearson J, Escalante G, Campbell B, De Souza EO. Body recomposition: can trained individuals build muscle and lose fat at the same time? Strength Cond J, 2020;42(5):7-21.
- Padwal R, Leslie WD, Lix LM, Majumdar SR. Relationship among body fat percentage, body mass index, and all-cause mortality: a cohort study. Ann Intern Med, 2016;164:532-41.
- Jayedi A, Khan TA, Aune D, Emadi A, Shab-Bidar S. Body fat and risk of all-cause mortality: a systematic review and dose-response meta-analysis of prospective cohort studies. Int J Obes, 2022;46:1573-81.