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BMR Calculator
LiveCalculate your BMR using the Mifflin-St Jeor equation.
Calculate your BMR using the Mifflin-St Jeor equation.
Basal Metabolic Rate (BMR) is the number of calories your body needs at complete rest to maintain vital functions — breathing, circulation, cell production, nutrient processing, and temperature regulation.
BMR accounts for 60-75% of your total daily energy expenditure (TDEE). The remaining energy is used for physical activity (15-30%) and digesting food (10%).
Several factors influence BMR:
Developed in 1990, the Mifflin-St Jeor equation is considered the most accurate formula for estimating BMR in the general population:
Male: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5
Female: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161
This formula has an accuracy of approximately ±10% compared to indirect calorimetry. It replaced the older Harris-Benedict equation, which tended to overestimate BMR by 5-15%.
BMR is what you burn at complete rest. TDEE (Total Daily Energy Expenditure) is BMR plus all your daily activity — walking, exercise, and digesting food. Use the activity-adjusted estimates above to see how your BMR translates to your total calorie needs.
Yes, the most effective way is to increase muscle mass through resistance training. Each kilogram of muscle burns about 13 extra calories per day at rest. High-protein diets and adequate sleep also support a healthy metabolic rate.
Prolonged severe calorie restriction can lower BMR by 10-20% as the body adapts to conserve energy (metabolic adaptation). This is why moderate deficits of 300-500 calories are recommended for weight loss, and why refeed days or diet breaks can help maintain metabolic rate.
Recalculate whenever your weight changes by 5-10 lbs (2-5 kg) or your body composition changes significantly. Since BMR depends on weight, height, and age, you only need to recalculate when one of those factors changes.
BMR (Basal Metabolic Rate) is measured under strict conditions — complete rest, after 8 hours of sleep, 12 hours of fasting. RMR (Resting Metabolic Rate) is measured under less strict conditions and is typically 5-10% higher than BMR. In practical use, the terms are often used interchangeably.