Fitness

Body recomposition calculator

Compare energy, protein, and body-composition scenarios using stated assumptions.

Free · No account neededMethod & sources

YOUR INPUTS

Your measurements

Measurement units

Use the sex category specified by the source equation.

Inputs stay in this browser.

YOUR RESULT

Start with your numbers.

Complete the fields to see the calculation, method, and limits.

UNDERSTAND THE METHOD

How to use this calculator

Enter body measurements, training experience, activity, and a scenario. The comparison score controls the recomposition energy scenario. The tables show every assumption. The 12-week illustration uses fixed monthly rates and does not update energy needs.

What the result can tell you

The comparison score and monthly rates are custom assumptions, not a validated prediction. The result does not establish whether recomposition will work for you. Body-fat error affects lean mass, FFMI, and every projection. A calorie comparison is not a prescription.

Common questions

What does the 12-week illustration assume?

It uses the selected comparison score and fixed monthly rates. The illustration does not update energy needs during the 12 weeks.

Does this result predict whether recomposition will work for me?

No. The comparison score and monthly rates are custom assumptions. Body-fat input error affects lean mass, FFMI, and every projection.

Sources & limitations

Sources checked September 12, 2026. These notes identify methods and assumptions. They have not received an independent clinical review.

  1. Review of body recomposition in trained people.doi.org
  2. Meta-analysis of protein supplementation and resistance training.pubmed.ncbi.nlm.nih.gov
  3. Protein intake during energy restriction in resistance-trained athletes.pubmed.ncbi.nlm.nih.gov
  4. Original FFMI research.pubmed.ncbi.nlm.nih.gov
How we check and update content