BMR and Calorie Needs: Understanding Your Metabolism
Explore Basal Metabolic Rate, how many calories your body burns at rest, and how to calculate your total daily energy expenditure for weight management.
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell production. It typically accounts for 60-75% of your total daily calorie expenditure.
The Mifflin-St Jeor Formula
Our calculator uses the Mifflin-St Jeor equation, considered the most accurate formula for estimating BMR. It accounts for weight, height, age, and gender. Men generally have higher BMRs than women due to greater muscle mass, and BMR decreases with age as muscle mass naturally declines.
Activity Multipliers
Your Total Daily Energy Expenditure (TDEE) is your BMR multiplied by an activity factor: Sedentary (1.2), Lightly Active (1.375), Moderately Active (1.55), Very Active (1.725), or Extremely Active (1.9). This gives you the total calories you burn daily including all activities.
Weight Management Applications
To lose weight, consume 500-750 calories below your TDEE for a safe 1-1.5 pound weekly loss. To gain weight, add 300-500 calories above TDEE. To maintain weight, match your calorie intake to your TDEE. These calculations provide a starting point that you can adjust based on results.
Factors Affecting Metabolism
Muscle mass, genetics, hormones, sleep quality, stress levels, and meal timing all influence metabolism. Building muscle through strength training increases BMR since muscle tissue burns more calories at rest than fat tissue. Adequate sleep and stress management also support healthy metabolic function.