About the BMR Calculator
BMR, or basal metabolic rate, estimates how many calories your body may use at rest for basic functions such as breathing, circulation, and temperature regulation.
How to Use It
Choose Metric or US units, enter age, sex, height, and weight, then select a formula. The calculator shows a resting calorie estimate and simple activity-based estimates.
Mifflin-St Jeor vs Harris-Benedict
Mifflin-St Jeor is a common modern default for adults. Revised Harris-Benedict is another established formula and may give a slightly different estimate.
BMR vs Daily Calories
BMR is not the same as daily calorie need. Daily needs also include activity, exercise, digestion, and normal movement, so use activity estimates as a starting point.
Limits and Source
BMR is predicted from population equations, not measured directly. Results can differ from an individual's true resting energy use and are not designed for children, pregnancy or breastfeeding, eating disorders, or medical nutrition treatment. The Mifflin-St Jeor equation used here is documented in this peer-reviewed study; consult a qualified clinician or dietitian for individualized care.