BMR Calculator
Calculate your basal metabolic rate at rest.
Know your body fat %? We'll use the more precise Katch-McArdle formula.
The calories you'd burn in a day of complete rest.
Compare formulas
Mifflin-St Jeor
Most accurate for the general population
Revised Harris-Benedict
Older formula, runs slightly higher
Estimated daily calories by activity level
For a full breakdown with goals, try the TDEE Calculator.
How to use it
- 1Choose your sex and unit system (metric or imperial).
- 2Enter your age, height, and weight — and your body fat % if you know it, for the more precise Katch-McArdle formula.
- 3Read your basal metabolic rate, how it compares across formulas, and estimated calories at each activity level.
Example
A 30-year-old man at 175 cm and 75 kg has a BMR of about 1,699 kcal/day by the Mifflin-St Jeor equation (1,763 by the older Harris-Benedict formula) — the energy his body needs just to stay alive at complete rest. At a moderate activity level that becomes roughly 2,633 kcal/day.
How it works
This uses the Mifflin-St Jeor equation by default, generally considered more accurate than the older Harris-Benedict formula: for men, BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5; for women, subtract 161 instead of adding 5. Both formulas are shown side by side so you can compare them. If you enter your body fat percentage, the calculator switches to the Katch-McArdle formula instead, which is based on lean body mass and is generally the most accurate of the three when that number is actually known. BMR itself doesn't include activity — the calories-by-activity-level breakdown gives a quick preview of that, or use the TDEE Calculator for the full version.