Calculate Basal Metabolic Rate and daily calorie needs
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest just to maintain basic functions like breathing, circulation, and cell repair. This calculator uses the Mifflin-St Jeor equation, the most widely used and accurate formula for estimating BMR.
Men: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5 | Women: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161
BMR is the baseline for calculating your total daily calorie needs (TDEE) — multiply BMR by an activity multiplier to find how many calories you burn in a typical day including activity.
It's considered one of the more accurate BMR formulas for the general population, typically within about 10% of measured values, though individual metabolism can vary due to genetics, muscle mass, and hormones.
Men typically have more lean muscle mass than women at the same height and weight, and muscle burns more calories at rest than fat, so the formula includes a different constant for each sex.
Yes — BMR is based partly on body weight, so as weight decreases, BMR typically decreases too, which is why calorie targets should be recalculated periodically during a diet.
No — eating only your BMR ignores the calories burned through daily activity and exercise, and can be too low to sustain; use your TDEE (BMR × activity level) as your baseline instead.