BMR Calculator
Free BMR calculator to find how many calories your body burns at rest using Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas.
Related Calculators
You might also find these calculators useful
Discover Your Basal Metabolic Rate (BMR)
Your Basal Metabolic Rate is the number of calories your body needs to perform basic life-sustaining functions like breathing, circulation, and cell production. Understanding your BMR is the foundation for any weight management or nutrition plan. Our calculator uses multiple scientifically-validated formulas to give you the most accurate estimate.
What Is BMR?
Basal Metabolic Rate (BMR) represents the minimum calories your body requires at complete rest—as if you stayed in bed all day. It accounts for 60-75% of your total daily calorie expenditure. Factors affecting BMR include age, sex, weight, height, muscle mass, and genetics. BMR decreases with age and increases with muscle mass.
Mifflin-St Jeor Equation (Most Accurate)
Men: BMR = (10 × weight) + (6.25 × height) - (5 × age) + 5How to Calculate BMR
Common Use Cases
Weight Loss Planning
Establish your baseline calorie needs to create an effective and safe calorie deficit.
Fitness & Bodybuilding
Determine minimum calorie intake to support muscle building without excessive fat gain.
Medical Nutrition
Healthcare professionals use BMR to calculate nutritional needs for patients.
Understanding Metabolism
Learn how your body uses energy at rest and how factors like age and muscle affect it.
Frequently Asked Questions
Mifflin-St Jeor is most accurate for most people and is recommended by the Academy of Nutrition and Dietetics. Use Katch-McArdle if you know your body fat percentage, as it accounts for muscle mass.