How it works
First the Mifflin-St Jeor BMR (basal metabolic rate):
BMR = 10·weight(kg) + 6.25·height(cm) − 5·age + s
where s = +5 for men and −161 for women. Then TDEE = BMR × activity factor (1.2 sedentary → 1.9 very active).
Worked example
A 30-year-old man, 180 cm, 80 kg, moderately active:
- BMR ≈ 1,780 kcal
- TDEE ≈ 1,780 × 1.55 ≈ 2,759 kcal/day to maintain
How we check this calculator
Daily-calorie estimates use the Mifflin-St Jeor equation, the formula with the best validation record in peer-reviewed comparisons, with activity multipliers from the standard published range (1.2–1.9). We verify against the equation's canonical worked examples and check that the deficit guidance stays within the commonly cited safe bounds (roughly 500–1,000 kcal/day for ~1–2 lb per week), re-testing male/female and metric/imperial paths after any change.