BMR Calculator
See the calories your body burns at complete rest with the Mifflin-St Jeor and Harris-Benedict equations.
Awaiting Data
Enter your details and tap Calculate to see your results appear here.
Your result appears here.
What BMR Measures
Your Basal Metabolic Rate is the energy your body spends just to stay alive. Breathing, pumping blood, and keeping warm all draw on this baseline, even while you sleep.
BMR makes up the largest slice of your daily calorie burn, often around 60 to 70 percent. Knowing it gives you the foundation for any calorie or weight goal.
Age, sex, height, and weight all shape the number. More muscle and a larger frame raise it.
How to Use This Calculator
- Pick metric or US units.
- Select your sex and enter age, height, and weight.
- Tap Calculate to see your BMR.
- Compare the two formulas shown.
The Formula Used
Men: BMR = 10·weight(kg) + 6.25·height(cm) − 5·age + 5
Women: BMR = 10·weight(kg) + 6.25·height(cm) − 5·age − 161
- weight
- Body weight in kilograms.
- height
- Standing height in centimetres.
- age
- Age in years.
Understanding Your Results
Tips to Improve
- Build muscle, since it burns more at rest than fat.
- Eat enough protein to protect lean mass.
- Avoid crash diets, which lower your BMR over time.
- Stay active daily to keep metabolism humming.
Frequently Asked Questions
BMR is your rest-only burn. TDEE adds the calories you spend moving through the day.
Mifflin-St Jeor is the modern standard and tends to beat the older Harris-Benedict for most adults.
Eating only at BMR creates a large deficit and is rarely safe. Base your target on TDEE instead.
Scientific References
- Mifflin, M. D., et al. (1990). A new predictive equation for resting energy expenditure. American Journal of Clinical Nutrition, 51(2), 241–247.
- Harris, J. A., & Benedict, F. G. (1918). A biometric study of human basal metabolism. PNAS, 4(12), 370–373.
- Frankenfield, D., et al. (2005). Comparison of predictive equations for resting metabolic rate. Journal of the American Dietetic Association, 105(5), 775–789.