BMR Calculator

Calculate your Basal Metabolic Rate (BMR) using scientifically proven formulas including Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle equations.

Enter Your Information
Enter your details to calculate your Basal Metabolic Rate (BMR) - the number of calories your body burns at rest.

Required for Katch-McArdle formula (3-50%)

BMR Formulas Explained

Mifflin-St Jeor Equation (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

Most accurate formula for general population, developed in 1990

Revised Harris-Benedict Equation

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)

Revised version of the original 1919 formula, updated in 1984

Katch-McArdle Formula

BMR = 370 + (21.6 × lean_body_mass_kg)

Lean Body Mass = weight_kg × (1 - body_fat_percentage/100)

Most accurate for lean individuals who know their body fat percentage

Important Notes

Accuracy: BMR calculations are estimates based on population averages. Individual metabolic rates can vary by ±20% due to genetics, muscle mass, hormone levels, and other factors.

Medical Disclaimer: These calculations are for informational purposes only. Always consult with a healthcare professional or registered dietitian before making significant dietary changes, especially if you have medical conditions or are taking medications that may affect metabolism.

Understanding BMR:

  • BMR: Calories burned at complete rest for basic bodily functions
  • RMR (Resting Metabolic Rate): Similar to BMR but measured under less strict conditions
  • TDEE: BMR multiplied by activity level to get total daily calories
  • Factors affecting BMR: Age, gender, body composition, genetics, hormones, temperature