BMR Calculator (Basal Metabolic Rate)
Calculate your Basal Metabolic Rate using the Harris-Benedict or Mifflin-St Jeor equation.
Find your daily calorie burn at rest.
Your Basal Metabolic Rate (BMR) is the number of calories your body burns just to stay alive — breathing, pumping blood, regulating temperature, and keeping organs functioning — while completely at rest.
Mifflin-St Jeor Equation (most accurate, recommended):
- Men: BMR = (10 × weight_kg) + (6.25 × height_cm) − (5 × age) + 5
- Women: BMR = (10 × weight_kg) + (6.25 × height_cm) − (5 × age) − 161
Original Harris-Benedict Equation (1919, widely used):
- Men: BMR = 88.362 + (13.397 × weight_kg) + (4.799 × height_cm) − (5.677 × age)
- Women: BMR = 447.593 + (9.247 × weight_kg) + (3.098 × height_cm) − (4.330 × age)
Why BMR matters: BMR typically accounts for 60–75% of your total daily calorie expenditure. Even if you do nothing all day, your body burns this many calories. Understanding your BMR helps you set realistic calorie targets for weight loss, maintenance, or muscle gain.
BMR vs TDEE: BMR is just the resting baseline. Your Total Daily Energy Expenditure (TDEE) multiplies BMR by an activity factor:
- Sedentary (desk job, no exercise): BMR × 1.2
- Lightly active (1–3 days/week): BMR × 1.375
- Moderately active (3–5 days/week): BMR × 1.55
- Very active (6–7 days/week): BMR × 1.725
- Extremely active (physical job + daily training): BMR × 1.9
Typical BMR ranges:
- Average adult woman: 1,400–1,600 kcal/day
- Average adult man: 1,700–2,000 kcal/day
- BMR decreases with age (about 2% per decade after 20)
- Muscle mass increases BMR — strength training raises your resting burn over time
Example (Mifflin-St Jeor): 30-year-old woman, 65 kg, 165 cm: BMR = (10 × 65) + (6.25 × 165) − (5 × 30) − 161 = 650 + 1031.25 − 150 − 161 = 1,370 kcal/day