BMR Calculator
Calculate your basal metabolic rate (BMR), the calories your body burns at complete rest to stay alive. It is the foundation of your daily calorie needs.
How the BMR calculator works
Your basal metabolic rate is the energy your body uses at rest for core functions like breathing, circulation, and cell repair. This calculator uses the Mifflin-St Jeor equation, the formula research finds most accurate for most people.
The Mifflin-St Jeor formula
BMR uses your weight, height, age, and sex. For men it is 10 times weight in kg, plus 6.25 times height in cm, minus 5 times age, plus 5. For women the last step is minus 161 instead of plus 5. Heavier, taller, and younger bodies burn more at rest.
BMR vs TDEE
BMR is only the calories you burn at rest. Your total daily burn, TDEE, is BMR multiplied by an activity factor for movement and exercise. To find the calories you actually need each day, use the TDEE or calorie calculator.
Frequently asked questions
What is BMR?
Basal metabolic rate (BMR) is the number of calories your body burns at complete rest over a day, just to keep essential functions running like breathing, circulation, and maintaining body temperature. It is the largest part of most people's daily calorie burn.
How is BMR calculated?
This calculator uses the Mifflin-St Jeor equation, which takes your weight, height, age, and sex. Studies have found it more accurate for the general population than older formulas like Harris-Benedict. It estimates resting calorie burn, not your total daily needs.
What is the difference between BMR and TDEE?
BMR is the calories you burn at rest. TDEE (total daily energy expenditure) is your full daily burn: BMR plus the energy used for daily activity, exercise, and digesting food. TDEE is BMR multiplied by an activity factor, and it is the number to use for weight goals.
Should I eat my BMR in calories?
No. BMR is only resting burn, so eating exactly your BMR would usually create a large deficit once daily activity is added. To lose, maintain, or gain weight, base your intake on your TDEE instead, then adjust from there. Eating well below your BMR for long is not recommended.
Why is my BMR different from someone at the same weight?
Height, age, and sex all change the result, so two people at the same weight can have different BMRs. Body composition matters too: muscle burns more at rest than fat, so the equation is an estimate. It will not capture every individual difference, but it is a solid starting point.