BMR Calculator

What is Basal Metabolic Rate (BMR)?

Your Basal Metabolic Rate (BMR) is the minimum number of calories your body needs to maintain vital functions at complete rest: breathing, blood circulation, body temperature, brain function, and cell renewal. It accounts for 60–75% of the total calories you burn each day. Knowing your BMR is the first step in any serious nutrition plan.

BMR formulas

Mifflin-St Jeor equation (most accurate according to recent studies):

• 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 equation (classic, slightly less precise):

• Men: BMR = 88.36 + 13.40×weight + 4.80×height − 5.68×age
• Women: BMR = 447.59 + 9.25×weight + 3.10×height − 4.33×age

Step-by-step example

Woman, 32 years old, 62 kg, 165 cm tall.

1. BMR (Mifflin) = 10×62 + 6.25×165 − 5×32 − 161
2. = 620 + 1,031.25 − 160 − 161 = 1,330 kcal/day
3. With moderate activity (3–5 days of exercise): 1,330 × 1.55 = 2,062 kcal/day maintenance

BMR and total daily energy expenditure (TDEE)

To calculate total daily calories, multiply your BMR by an activity factor:

• Sedentary (no exercise): BMR × 1.2
• Light activity (1–3 days/week): BMR × 1.375
• Moderate activity (3–5 days/week): BMR × 1.55
• Intense activity (6–7 days/week): BMR × 1.725
• Athlete or very intense physical work: BMR × 1.9

BMR applications in nutrition

• Weight loss: Eat 300–500 kcal below your TDEE to lose 0.3–0.5 kg/week sustainably.
• Muscle gain: Caloric surplus of 200–300 kcal above TDEE with sufficient protein (1.6–2.2 g/kg).
• Maintenance: Eat at your calculated TDEE and adjust every 2–4 weeks based on actual weight changes.
• Athletes: In high-volume sports, TDEE can exceed 4,000–5,000 kcal/day.