Cutting Calculator

A cutting phase in bodybuilding targets body fat reduction while preserving as much lean muscle mass as possible. This requires a calculated calorie deficit — large enough to burn fat, small enough to prevent muscle catabolism.

Step 1 — Calculate TDEE (Total Daily Energy Expenditure): TDEE = BMR × Activity Multiplier BMR (Mifflin-St Jeor, male) = 10×weight(kg) + 6.25×height(cm) − 5×age + 5 BMR (Mifflin-St Jeor, female) = 10×weight(kg) + 6.25×height(cm) − 5×age − 161

Activity multipliers:

• Sedentary (desk job, no exercise): × 1.2
• Light activity (1–3 days/week): × 1.375
• Moderate (4–5 days/week): × 1.55
• Very active (6–7 days/week, intense): × 1.725

Step 2 — Apply the deficit: Cutting Calories = TDEE − Deficit

• Conservative cut: −250 kcal/day → ~0.5 lb (0.23 kg) fat loss per week
• Standard cut: −500 kcal/day → ~1 lb (0.45 kg) fat loss per week
• Aggressive cut: −750 kcal/day → ~1.5 lb fat loss per week (muscle loss risk increases)

Worked example: Male, 85 kg, 180 cm, 28 years old, trains 5 days/week. BMR = 10×85 + 6.25×180 − 5×28 + 5 = 850 + 1,125 − 140 + 5 = 1,840 kcal TDEE = 1,840 × 1.55 = 2,852 kcal Standard cut target: 2,852 − 500 = 2,352 kcal/day

Protein during a cut: Aim for 1.8–2.4 g protein per kg of body weight to preserve muscle. At 85 kg: 153–204 g protein per day minimum.