What Is Basal Metabolic Rate (BMR)?
Your Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic physiological functions — breathing, circulation, cell production, and temperature regulation — while at complete rest for 24 hours. It represents the minimum energy required to keep you alive.
Harris-Benedict BMR Formula (Revised Mifflin-St Jeor)
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)
Women: BMR = 447.593 + (9.247 × weight kg) + (3.098 × height cm) − (4.330 × age)
What Affects Your BMR?
- Muscle mass: Muscle burns ~3× more calories at rest than fat tissue
- Age: BMR decreases approximately 2% per decade after age 20
- Body size: Larger bodies require more energy to maintain
- Gender: Men typically have 5–10% higher BMR due to greater muscle mass
- Hormones: Thyroid disorders can significantly raise or lower BMR
BMR vs TDEE vs Calories
BMR is your baseline. Multiply it by your activity factor to get TDEE (Total Daily Energy Expenditure) — the actual calories you need each day. Eating at TDEE maintains weight; eating 500 kcal below causes ~0.5 kg/week fat loss.
Note: BMR calculations are estimates with ±10% accuracy. Individual metabolism varies due to genetics, hormones, and body composition not captured by height/weight alone.