BMR Calculator
Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic physiological functions at complete rest — breathing, circulation, temperature regulation, and cell production.
How BMR is Calculated
Two formulas are commonly used to estimate BMR.
Mifflin-St Jeor (Recommended)
Developed in 1990, this is the most clinically validated formula for the general population.
Men: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) + 5
Women: BMR = (10 × weight kg) + (6.25 × height cm) − (5 × age) − 161
Harris-Benedict (Revised)
The original formula, revised in 1984. Slightly higher estimates than 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) − (4.33 × age)
BMR vs TDEE
BMR is just the starting point. To estimate total daily calorie needs, multiply your BMR by an activity multiplier:
| Activity Level | Multiplier |
|---|---|
| Sedentary (little or no exercise) | × 1.2 |
| Lightly active (1–3 days/week) | × 1.375 |
| Moderately active (3–5 days/week) | × 1.55 |
| Very active (6–7 days/week) | × 1.725 |
| Extra active (physical job or 2x training) | × 1.9 |
Limitations
BMR formulas use population-level equations and are estimates. Individual BMR can vary based on genetics, body composition, hormones, and health conditions. For precise measurements, indirect calorimetry is the gold standard.