Find how many calories your body burns at complete rest (basal metabolic rate), with the Mifflin-St Jeor formula and a Harris-Benedict comparison.
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Enter weight, height, age and sex. We compute BMR with the Mifflin-St Jeor formula.
BMR = energy burned at complete rest. For your real daily need, multiply by your activity factor (see the TDEE calculator).
BMR ≈ 1,649 kcal/dayInformational estimates, not medical advice. We use standard formulas (WHO, Mifflin-St Jeor, US Navy method). Instant in-browser calculation, no account, no data sent. For medical decisions, consult a professional.
BMR (basal metabolic rate) is the energy burned at rest. The Mifflin-St Jeor formula estimates it from weight, height, age and sex:
For a man of 70 kg, 175 cm, 30 years: BMR = 700 + 1093.75 − 150 + 5 ≈ 1649 kcal/day.
BMR is the number of calories your body burns at complete rest, just for vital functions: breathing, circulation, maintaining temperature. It is the foundation of your daily calorie need.
The Mifflin-St Jeor formula: for men, BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5; for women subtract 161 instead of adding 5.
Both estimate BMR from weight, height, age and sex. Mifflin-St Jeor (1990) is considered more accurate for today’s population; Harris-Benedict is the classic formula, revised in 1984.
BMR is your resting burn, while TDEE (total daily need) is BMR multiplied by an activity factor. TDEE is always higher because it includes movement and digestion.
As you age, muscle mass declines, and muscle burns more energy than fat. So at the same weight an older person has a lower BMR.
At the same weight and height, men generally carry a higher percentage of muscle, so they burn more calories at rest.
It is not advised. Eating below BMR long term can slow your metabolism and cause muscle loss. A calorie deficit is usually set below TDEE but above BMR.
The formulas have a margin of about ±10%, because they do not account for exact body composition. Precise measurement requires indirect calorimetry.
By building muscle mass (strength training), staying hydrated and sleeping enough. Muscle mass is the main factor that raises resting metabolism.