Calculate your Total Daily Energy Expenditure with the Mifflin-St Jeor equation — BMR, activity-adjusted calories, and cutting/bulking targets.
A 28-year-old man, 5’10” (177.8 cm), 170 lb (77.1 kg), training 4×/week: BMR = 10(77.1) + 6.25(177.8) − 5(28) + 5 = 771 + 1,111 − 140 + 5 = 1,747 kcal. Moderately active multiplier ×1.55 → TDEE = 2,708 kcal/day. The same person with a desk job and no training (×1.2) burns just 2,096 — a 600-calorie difference that dwarfs any formula error, which is why the multiplier, not the equation, is where estimates go wrong.
Using ~3,500 kcal per pound of body weight: a 500 kcal/day deficit ≈ 1 lb/week; the moderate −10% cut from the table (~270 kcal at this TDEE) ≈ 0.5 lb/week. Cuts beyond 25% trade muscle and adherence for speed; surpluses beyond ~10% mostly add fat once training capacity is saturated. Recalculate after every 10-15 lb change — TDEE moves with body size. To turn a calorie target into food, split it with our macro calculator, and track the walking side with the steps to miles calculator.
Mifflin-St Jeor assumes average body composition. Very muscular people run hotter than predicted (muscle is metabolically active) — the Katch-McArdle equation, which starts from lean mass, fits them better; pair it with our body fat percentage calculator to get lean mass first. Formulas also drift for older adults and during aggressive dieting (metabolic adaptation of 5-15%). Treat the number as a starting hypothesis: three weeks of scale trend beats any equation.
Convert daily calories into grams of protein, carbs, and fat — five evidence-based splits with the 4/4/9 conversion math shown.
Plan your weight loss journey by target date with personalized calorie and exercise recommendations.
Calculate your body fat percentage using Navy method or BMI method with step-by-step solutions and multiple calculation methods.