What Is a BMR Calculator?
A BMR calculator estimates your Basal Metabolic Rate, which represents the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell production.
BMR Formula (Mifflin-St Jeor Equation)
For Men:
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5
For Women:
BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161
Example Calculation
Male, 30 years old, 70 kg, 175 cm:
BMR = (10 × 70) + (6.25 × 175) − (5 × 30) + 5
BMR = 700 + 1093.75 − 150 + 5
BMR = 1648.75 kcal/day
Total Daily Energy Expenditure (TDEE)
TDEE = BMR × Activity Multiplier
- Sedentary: BMR × 1.2
- Light activity: BMR × 1.375
- Moderate activity: BMR × 1.55
- Very active: BMR × 1.725
- Extra active: BMR × 1.9
Why BMR Matters
Understanding your BMR helps with weight loss, muscle gain, and calorie planning.
Limitations
BMR is an estimate. Actual metabolism varies due to genetics, hormones, and body composition.