Basal Metabolic Rate (BMR) Calculator

Calculate your Basal Metabolic Rate (BMR) to determine how many calories your body needs at rest to maintain basic functions like breathing, circulation, and cell production. Your BMR represents the minimum amount of energy needed to keep your body functioning.

How the BMR Calculator Works

The BMR calculator uses scientifically validated formulas to estimate your Basal Metabolic Rate based on your gender, age, height, and weight.

Mifflin-St Jeor Formula (Recommended)

For men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(y) + 5
For women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(y) - 161

Harris-Benedict Formula

For men: BMR = 13.397 × weight(kg) + 4.799 × height(cm) - 5.677 × age(y) + 88.362
For women: BMR = 9.247 × weight(kg) + 3.098 × height(cm) - 4.330 × age(y) + 447.593

Katch-McArdle Formula

BMR = 370 + 21.6 × Lean Body Mass(kg)
where Lean Body Mass = Weight(kg) × (100 - Body Fat %)/100

Daily Calorie Needs

To estimate total daily calorie needs, BMR is multiplied by an activity factor:

  • Sedentary (little or no exercise): BMR × 1.2
  • Light activity (light exercise 1-3 days/week): BMR × 1.375
  • Moderate activity (moderate exercise 3-5 days/week): BMR × 1.55
  • Active (hard exercise 6-7 days/week): BMR × 1.725
  • Very active (very hard exercise & physical job): BMR × 1.9

The Mifflin-St Jeor equation is considered the most accurate for most people. The Harris-Benedict equation tends to overestimate BMR by about 5%. The Katch-McArdle formula can be more accurate for lean, physically active individuals since it accounts for body composition.