What is BMR?

BMR is the minimum number of calories your body needs to function at rest — before any physical activity is considered.

1. Mifflin-St Jeor Equation (Modern & Widely Used)

Most accurate for general population without knowing body fat %.

• Men:

  BMR=10×weight (kg)+6.25×height (cm)−5×age+5BMR

• Women:

  BMR=10×weight (kg)+6.25×height (cm)−5×age−161BMR

2. Revised Harris-Benedict Equation (Updated from 1918 version)

An older method, still used, but less accurate than Mifflin for modern body types.

• Men:

  BMR=88.362+(13.397×weight (kg))+(4.799×height (cm))−(5.677×age)BMR 

• Women:

  BMR=447.593+(9.247×weight (kg))+(3.098×height (cm))−(4.330×age)BMR

3. Katch-McArdle Equation (Best if body fat % is known)

Does not depend on gender or age, but requires lean mass:

BMR=370+(21.6×Lean Body Mass (kg))

• Lean Body Mass = Weight × (1 − Body Fat % in decimal)

Example:
If weight = 70 kg and body fat = 20%,
Lean mass = 70 × (1 − 0.20) = 56 kg
BMR = 370 + (21.6 × 56) = 1579.6 kcal/day