Body Recomposition Calculator

Body recomposition means losing fat and building muscle at the same time — changing how you look without necessarily changing the number on the scale. The winning recipe is eating at roughly maintenance calories, keeping protein high, and training hard with progressive resistance work. This calculator estimates your maintenance calories and splits them into recomp-friendly macros.

The Method

We start with the Mifflin-St Jeor BMR, scale it by your activity level to get TDEE (maintenance), then build macros around a high protein anchor.

Worked Example

A 30-year-old man, 75 kg, 178 cm, moderately active (×1.55):

• BMR = 10×75 + 6.25×178 − 5×30 + 5 = 1,718 kcal
• Maintenance = 1,718 × 1.55 ≈ 2,663 kcal
• Protein = 2.2 × 75 = 165 g (660 kcal)
• Fat = 25% of 2,663 ≈ 74 g (666 kcal)
• Carbs = remaining 1,337 kcal ≈ 334 g

Who Recomposition Works Best For

Why Maintenance Calories?

A large deficit stalls muscle growth; a large surplus adds fat. Eating around maintenance lets your body pull energy from fat stores to build muscle when protein and training stimulus are high. Progress shows up in the mirror, in strength gains, and in body-fat measurements rather than on the scale.

Dialing It In

Keep protein near 2 g/kg, train each muscle 2-3 times weekly with progressive overload, prioritise sleep, and reassess every 4-6 weeks. If you are gaining fat, trim 100-150 kcal; if strength is stalling and you look flat, add a little back.

Note: These are estimated starting targets, not a prescription. Individual energy needs vary with genetics and NEAT. Consult a registered dietitian or qualified coach for personalised programming.