BMR Calculator

BMR is the number of calories your body burns at complete rest to keep vital functions running — breathing, circulation, cell production, and temperature regulation. It typically accounts for 60–70% of the calories you burn each day.

This calculator uses the Mifflin-St Jeor equation, considered the most accurate for the general population. Men: BMR = 10·weight(kg) + 6.25·height(cm) − 5·age + 5. Women: the same but − 161 instead of + 5. It also shows the older Harris-Benedict result for comparison.

BMR is what you burn at rest. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor to account for movement and exercise. TDEE is always higher than BMR — it's the figure you use to plan calorie intake.

Mifflin-St Jeor (1990) is generally preferred because it was validated on a modern population and tends to be more accurate, within about 10% for most people. The revised Harris-Benedict (1984) is still widely cited and usually lands within a few percent of Mifflin for typical adults.

BMR tends to fall as you age because you usually lose lean muscle mass, which is more metabolically active than fat. Strength training and adequate protein help preserve muscle and keep your BMR higher.