This calculator uses the Mifflin-St Jeor equation — the estimate recommended by the Academy of Nutrition and Dietetics for resting metabolic rate — then multiplies by a standard activity factor and applies a gradual ±500 kcal goal adjustment.
Formula & methodology
BMR (men) = 10·kg + 6.25·cm − 5·age + 5; BMR (women) = 10·kg + 6.25·cm − 5·age − 161. Maintenance (TDEE) = BMR × activity factor (1.2 sedentary → 1.9 very active). Goal: ±500 kcal/day ≈ ±0.45 kg/week of gradual change.
Worked example
Male, 30, 80 kg, 180 cm, sedentary → BMR 1,780 kcal, maintenance 2,136 kcal, gradual-loss target 1,636 kcal.
Limits — read this
These are population estimates with real individual spread (±10% is common). Adults only; not for pregnancy, medical conditions, or eating-disorder recovery. Targets below 1,200 kcal trigger a warning — do not follow them without professional supervision. This is information, not medical or dietary advice.