BMR Calculator

Estimate your Basal Metabolic Rate (calories burned at rest).

Select units, enter details, choose formula, and calculate.

BMR represents calories burned at complete rest. Multiply by an activity factor (using our Calorie/TDEE calculator) for total daily needs.

Understanding Your Basal Metabolic Rate (BMR)

Your Basal Metabolic Rate (BMR) is the minimum number of calories your body requires to perform its most basic, life-sustaining functions while at rest. This includes processes like breathing, circulating blood, regulating body temperature, cell production, and nutrient processing.

Knowing your BMR is the first step in determining your Total Daily Energy Expenditure (TDEE), which accounts for the calories burned through physical activity. BMR typically accounts for the largest portion of your daily calorie burn.

How to Use the BMR Calculator

  1. Select your preferred unit system (Metric or Imperial).
  2. Enter your Age in years.
  3. Select your biological Gender.
  4. Enter your current Weight and Height in the chosen units.
  5. Choose the BMR formula you wish to use (Mifflin-St Jeor is generally considered more accurate for most people, but the Revised Harris-Benedict is also provided).
  6. Click "Calculate BMR".

The calculator will display your estimated BMR in calories per day.

Common BMR Formulas

  • Mifflin-St Jeor Equation:
    • Men: BMR = (10 * weight in kg) + (6.25 * height in cm) - (5 * age in years) + 5
    • Women: BMR = (10 * weight in kg) + (6.25 * height in cm) - (5 * age in years) - 161
  • Revised Harris-Benedict Equation:
    • Men: BMR = (13.397 * weight in kg) + (4.799 * height in cm) - (5.677 * age in years) + 88.362
    • Women: BMR = (9.247 * weight in kg) + (3.098 * height in cm) - (4.330 * age in years) + 447.593

Factors Influencing BMR

BMR is influenced by several factors, including:

  • Body Size & Composition: Larger individuals and those with more muscle mass generally have higher BMRs.
  • Gender: Men typically have more muscle mass and thus a higher BMR than women of the same size and age.
  • Age: BMR generally decreases with age due to muscle loss and metabolic changes.
  • Genetics: Some individuals naturally have faster or slower metabolisms.
  • Hormones & Health Conditions: Thyroid function and other factors can impact BMR.

Use your BMR as a baseline. To estimate your total daily calorie needs (TDEE) for weight management, multiply your BMR by an activity factor using our separate Calorie Calculator.