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BMR calculator.
The energy your body uses at rest in a day: your basal metabolic rate, in kilojoules and calories.
How it works
The Mifflin-St Jeor equation.
Mifflin-St Jeor predicts the energy you'd use lying still for a day from your weight, height, age and sex. It was published in 1990 and came out the most accurate of the common equations for healthy adults in a later systematic review.
Men: BMR = 10 × kg + 6.25 × cm − 5 × age + 5
Women: BMR = 10 × kg + 6.25 × cm − 5 × age − 161
The result is in kcal a day; × 4.184 gives kJ. Example: a 30-year-old man, 180 cm, 80 kg: 800 + 1,125 − 150 + 5 = 1,780 kcal (7,448 kJ).Limits
- Lands within 10% of a measured BMR for most healthy adults, not all.
- Older adults and some ethnic groups were under-represented in the studies behind it.
- It can't see muscle. Two people with the same weight can have quite different BMRs.
- For adults 18 and over. Not for pregnancy.
Sources
- Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. American Journal of Clinical Nutrition 51(2):241 to 247, 1990.
- Frankenfield D, Roth-Yousey L, Compher C. Comparison of predictive equations for resting metabolic rate in healthy nonobese and obese adults: a systematic review. Journal of the American Dietetic Association 105(5):775 to 789, 2005.