Calculator Lab
🔍

BMR Calculator

Calculate your Basal Metabolic Rate - the calories your body burns at rest using Mifflin-St Jeor formula.

Share:

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic life-sustaining functions like breathing, circulation, and cell production while at complete rest.

Your actual daily calorie needs (TDEE) = BMR × Activity Multiplier

Advertisement

How to Use This Calculator

  1. Choose between US Units (pounds, feet, inches) or Metric (kg, cm)
  2. Enter your age in years
  3. Select your biological gender (affects the calculation formula)
  4. Input your current weight
  5. Enter your height (feet and inches for US, centimeters for metric)
  6. Click 'Calculate BMR' to see your results
  7. Review results from all three formulas for comparison
  8. Check the activity level table to see your total daily calorie needs

Formula

Mifflin-St Jeor: BMR (Male) = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5; BMR (Female) = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161; Harris-Benedict (Revised): Male = 88.362 + 13.397 × weight(kg) + 4.799 × height(cm) - 5.677 × age; Female = 447.593 + 9.247 × weight(kg) + 3.098 × height(cm) - 4.330 × age

Frequently Asked Questions

What is BMR and why is it important?▼
BMR (Basal Metabolic Rate) is the number of calories your body needs to perform basic life-sustaining functions at rest. It represents 60-75% of your total daily calorie expenditure and is crucial for understanding your baseline energy needs.
Which BMR formula is most accurate?▼
The Mifflin-St Jeor equation is generally considered the most accurate for the general population. It was developed in 1990 and has been validated across various studies. However, the Katch-McArdle formula is more accurate if you know your body fat percentage.
How do I use my BMR for weight management?▼
Multiply your BMR by your activity level (1.2-1.9) to get your TDEE (Total Daily Energy Expenditure). To lose weight, eat 10-20% below TDEE. To gain weight, eat 10-20% above TDEE. To maintain, eat at TDEE.
Why do different formulas give different results?▼
Each formula was developed using different population samples and methodologies. The differences are usually within 100-200 calories. The Mifflin-St Jeor tends to be most accurate for modern populations, while Harris-Benedict slightly overestimates for most people.
Advertisement