How to calculate your BMR
- Choose male or female and your units.
- Enter your age, height and weight.
- Add your body fat percentage if you know it, from a scan or the body fat calculator.
- Your BMR is highlighted; your maintenance calories are shown next to it.
About basal metabolic rate
Your BMR is the energy needed to keep you alive at complete rest: breathing, pumping blood, maintaining body temperature and repairing cells. For most adults it is between 1,200 and 2,000 kcal a day and makes up the largest share of daily energy use. It rises with body size and muscle mass and gradually falls with age.
The Mifflin-St Jeor equation (1990) is recommended by the Academy of Nutrition and Dietetics as the most reliable predictive formula for healthy people: for a 30-year-old man who is 180 cm tall and weighs 80 kg, BMR = 10 × 80 + 6.25 × 180 − 5 × 30 + 5 = 1,780 kcal. If you know your body fat, the Katch-McArdle formula uses lean body mass instead, which is more accurate for very muscular or very lean people. Eating below your BMR for long periods is not recommended without medical supervision.
ℹ️ Not medical advice: an estimate for healthy adults. Ask a doctor or qualified professional about your own situation.
FAQ
What is the difference between BMR and RMR?
Resting metabolic rate is measured under less strict conditions and is usually a little higher. In practice they are used interchangeably.
Can I raise my BMR?
Building muscle raises it slightly. Crash dieting tends to lower it.
Is the older Harris-Benedict formula better?
It tends to overestimate by about 5%. Mifflin-St Jeor is more accurate for today's populations.