BMR Calculator - Basal Metabolic Rate (Mifflin-St Jeor & Harris-Benedict)
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest — just to maintain vital functions like breathing, circulation, and cell production. It accounts for about 60-75% of your total daily energy expenditure. Your BMR is influenced by age, gender, weight, height, and muscle mass. Knowing your BMR is the first step in weight management: it helps you understand how many calories your body needs before any physical activity. This BMR calculator uses both the Mifflin-St Jeor (considered most accurate) and Harris-Benedict (original formula) equations. Higher muscle mass increases BMR, which is why strength training is excellent for weight management.
Why Use a BMR Calculator?
Your Basal Metabolic Rate (BMR) is the foundation of any weight loss, weight gain, or maintenance plan. By calculating your BMR, you can determine your Total Daily Energy Expenditure (TDEE) and set accurate calorie targets. Whether you're an athlete, bodybuilder, or just starting your fitness journey, knowing your BMR helps you make informed decisions about nutrition and exercise.
BMR Formulas Explained
Mifflin-St Jeor Equation (1990): Considered the most accurate BMR formula by the Academy of Nutrition and Dietetics. For men: (10 × weight in kg) + (6.25 × height in cm) - (5 × age) + 5. For women: (10 × weight in kg) + (6.25 × height in cm) - (5 × age) - 161.
Harris-Benedict Equation (1919): Original BMR formula, revised in 1984. Still widely used. For men: 66.5 + (13.75 × weight in kg) + (5.003 × height in cm) - (6.75 × age). For women: 655.1 + (9.563 × weight in kg) + (1.85 × height in cm) - (4.676 × age).