BMR formulas
Mifflin-St Jeor (1990)
Men: 10W + 6.25H − 5A + 5
Women: 10W + 6.25H − 5A − 161
Women: 10W + 6.25H − 5A − 161
Revised Harris-Benedict (Roza & Shizgal, 1984)
Men: 88.362 + 13.397W + 4.799H − 5.677A
Women: 447.593 + 9.247W + 3.098H − 4.330A
Women: 447.593 + 9.247W + 3.098H − 4.330A
Katch-McArdle
BMR = 370 + 21.6 × Lean body mass (kg)
W is weight in kilograms, H height in centimeters and A age in years.
Example: A 25-year-old woman, 165 cm (5 ft 5 in) and 60 kg (132 lb). Mifflin-St Jeor: 600 + 1,031.25 − 125 − 161 = 1,345 kcal/day. Revised Harris-Benedict gives about 1,405 kcal/day. The two equations typically differ by 5–10%.
What influences BMR
- Body size and composition — larger bodies and more muscle burn more energy.
- Age — BMR falls by roughly 1–2% per decade after early adulthood.
- Sex — men usually have a higher BMR because of greater lean mass.
- Genetics, hormones and health — thyroid function in particular has a large effect.
Equations estimate average BMR; an individual’s measured value can differ by 10% or more. Only indirect calorimetry measures it directly.
Frequently asked questions
What is BMR?
Basal metabolic rate is the energy your body uses at complete rest to keep you alive — breathing, circulating blood, maintaining body temperature and repairing cells. It usually accounts for 60–70% of the calories you burn each day.
What is the difference between BMR and TDEE?
TDEE (total daily energy expenditure) is BMR plus the calories used for activity, exercise and digesting food. To find how much to eat, use TDEE — our calorie calculator calculates it for you.
Which BMR formula is most accurate?
For most healthy adults, Mifflin-St Jeor is considered the most accurate of the common prediction equations. If you know your body fat percentage, Katch-McArdle can be better for lean or very muscular people because it uses lean body mass.
Can I increase my BMR?
Building muscle through strength training raises BMR modestly, because muscle tissue burns more energy at rest than fat. BMR naturally declines with age, largely due to loss of muscle.