BMR formulas
Mifflin-St Jeor (1990)
Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
Harris-Benedict, revised (1984)
Men: 88.362 + 13.397 × W + 4.799 × H − 5.677 × age
Women: 447.593 + 9.247 × W + 3.098 × H − 4.330 × age
Katch-McArdle
BMR = 370 + 21.6 × lean body mass (kg)
W = weight in kg, H = height in cm.
BMR vs. daily calories
BMR is usually 60–70% of the calories you burn in a day. The rest comes from moving, exercise and digesting food. Your total daily need is your TDEE.
What affects your BMR
- Muscle: more muscle means a higher BMR.
- Age: BMR falls slowly with age.
- Sex: men usually have a higher BMR because they carry more muscle.
- Size: taller and heavier people burn more.
- Thyroid: an underactive thyroid lowers BMR; get it checked if you have symptoms.
Frequently asked questions
What is a normal BMR?
For many adults BMR falls roughly between 1,200 and 2,000 kcal a day, depending on size, sex, age and muscle.
Which BMR formula is most accurate?
A systematic review found Mifflin-St Jeor the most accurate for most healthy adults. Katch-McArdle is good if you know your body fat.
Can I increase my BMR?
Yes, mainly by building muscle with strength training. Eating enough protein and staying active also help.
Should I eat only my BMR calories to lose weight?
Usually not. Eating at BMR is often too low. Base your diet on your TDEE minus a moderate deficit.
Sources
- Mifflin MD, St Jeor ST, et al. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition, 1990. Link
- Roza AM, Shizgal HM. The Harris Benedict equation reevaluated. American Journal of Clinical Nutrition, 1984. Link
- Frankenfield D, et al. Comparison of predictive equations for resting metabolic rate in healthy adults: a systematic review. Journal of the American Dietetic Association, 2005.
Last updated: 20 October 2026. Read our editorial policy.
