Body Recomposition Calculator
Get a calorie and protein target for losing fat while building or maintaining muscle at the same time, based on your TDEE, body fat, and training status.
Updated August 3, 2026
Medical Disclaimer: This tool provides general estimates for educational and informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare professional or registered dietitian before making significant changes to your diet, exercise, or health routine. Read our full Medical Disclaimer.
How This Is Calculated
No single validated ‘recomp formula’ exists. Instead, this calculator builds around the two levers the evidence supports for losing fat while building or maintaining muscle: a modest calorie deficit and adequate protein intake.
Step 1: Determine Your TDEE
You can either enter your daily calorie target directly, or let us estimate it from your stats using the same Mifflin-St Jeor / TDEE method used by our TDEE Calculator.
Step 2: Apply a Small Deficit
Rather than a large deficit, we apply a smaller one — roughly 10–20% below your TDEE. Aggressive deficits work against simultaneous muscle building, so recomposition trades speed for a better shot at holding onto (or gaining) muscle while losing fat.
Calorie target = TDEE × (0.80 to 0.90)
Step 3: Set a Protein Target
We set protein at 1.6–2.2 g per kg of bodyweight per day (roughly 0.7–1 g per lb) — the range with the strongest support for preserving or building muscle in a calorie deficit. We also break this into a rough per-meal count, since one large daily number is harder to act on mid-day.
Protein target (g/day) = Weight (kg) × 1.6 to 2.2
Step 4: Factor In Body Fat and Training Status
Recomposition is most realistic for beginners, returning trainees, or people with higher body fat percentages — they can often lose fat and build muscle at the same time. It’s still possible for lean, already-trained individuals, but progress is typically much slower, which we reflect in your result based on your training status.
A Note on Accuracy
Body recomposition is the slowest of the goal-based approaches — set pace expectations honestly. Resistance training is a stated prerequisite; the calorie and protein numbers alone don't build or preserve muscle without a training stimulus. No single validated recomposition formula exists, so this builds around the two levers with the strongest evidence: a modest deficit and adequate protein.
Frequently Asked Questions
Why Is the Deficit Smaller Than Other Weight-Loss Calculators?
A large calorie deficit works against building or maintaining muscle. Recomposition uses a smaller deficit (about 10–20% below TDEE) so you're losing fat slowly enough that your body can still support muscle growth or preservation with adequate protein and training.
Why Is My Protein Target a Range Instead of One Number?
Protein needs for preserving or building muscle in a deficit fall in a range (1.6–2.2 g/kg bodyweight per day) depending on training experience, body fat level, and individual factors. We show a range and a per-meal breakdown rather than pretending to more precision than the evidence supports.
Is Body Recomposition Realistic for Everyone?
It's most realistic for beginners, returning trainees, or people with higher body fat percentages, since they can often lose fat and gain muscle at the same time. It's still possible for lean, already-trained individuals, but progress is typically much slower — this calculator reflects that through your training-status input.
Do I Still Need to Lift Weights for This to Work?
Yes. Resistance training is a prerequisite, not optional. The calorie and protein targets create the right conditions, but a training stimulus is what actually signals your body to build or preserve muscle.
Sources
A systematic review of dietary protein during caloric restriction in resistance trained lean athletes — Helms, Aragon & Fitschen (2014), Journal of the International Society of Sports Nutrition, 11:20
Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss — Longland et al. (2016), American Journal of Clinical Nutrition, 103(3)