BMR Calculator
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest to keep vital functions running: breathing, circulation, and cell production. This calculator estimates your BMR with proven formulas such as Mifflin-St Jeor, then multiplies it by your activity level to estimate total daily calorie needs.
Your results
Enter your age, height, and weight to see your BMR and daily calorie needs.
How to calculate your BMR
- Enter your age, sex, height, and weight.
- Pick a formula. Mifflin-St Jeor is the most accurate for most people.
- Read your BMR: the calories your body needs at complete rest.
- Select your activity level to estimate your total daily energy expenditure (TDEE).
Frequently Asked Questions
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body needs to perform essential functions while at rest. It represents the minimum energy required to keep your body functioning, including breathing, circulation, cell production, and basic neurological functions.
How is BMR different from TDEE?
BMR only accounts for the calories needed for basic body functions at complete rest. Total Daily Energy Expenditure (TDEE) includes BMR plus calories burned through physical activity, digestion (thermic effect of food), and non-exercise activity thermogenesis (NEAT). TDEE represents your total daily calorie needs.
Why does the calculator use different formulas?
Different BMR formulas (Mifflin-St Jeor, Harris-Benedict, etc.) were developed using different research methodologies and population samples. The Mifflin-St Jeor equation is generally considered the most accurate for most people, but other formulas may work better for specific populations.
How can I use BMR for weight management?
For weight loss, consume fewer calories than your TDEE (BMR × activity factor); for weight gain, consume more. A deficit or surplus of 500-1000 calories daily can lead to approximately 1-2 pounds of weight change per week. Always combine calorie management with proper nutrition and regular exercise.
What factors affect my BMR?
BMR is influenced by age (decreases with age), gender (typically higher in males), body composition (muscle burns more calories than fat), genetics, hormones (thyroid issues can affect BMR), physical condition, and environmental temperature. Medical conditions and medications can also impact BMR.
Last updated: