BMR Calculator
Calculate your Basal Metabolic Rate (BMR) and discover how many calories your body burns at rest. Get personalized daily calorie needs based on your activity level for effective weight management and fitness planning.
BMR Calculator
Activity Level Guide
How to Use the BMR Calculator
- Choose Unit System: Select metric (kg, cm) or imperial (lbs, inches) units
- Select Gender: Choose male or female as this affects the calculation formula
- Enter Age: Input your age in years (15-120 years accepted)
- Enter Weight: Input your current weight in kg or pounds
- Enter Height: Input your height in centimeters or inches
- Calculate BMR: Click calculate to see your Basal Metabolic Rate and daily calorie needs
- Choose Activity Level: Use the activity guide to find your appropriate daily calorie target
Understanding Your BMR Results
What is BMR?
Basal Metabolic Rate
The number of calories your body needs to maintain basic physiological functions while at rest, including breathing, circulation, cell production, and brain function.
Why BMR Matters
BMR typically accounts for 60-75% of your total daily energy expenditure. Understanding your BMR helps set realistic calorie targets for weight loss, maintenance, or gain.
Mifflin-St Jeor Equation
Our calculator uses the scientifically validated Mifflin-St Jeor equation, considered one of the most accurate methods for estimating BMR.
Using Your Results
Weight Loss
Create a calorie deficit by eating 500-750 calories below your activity level needs for 1-2 pounds weight loss per week.
Weight Maintenance
Eat approximately the number of calories shown for your activity level to maintain your current weight.
Weight Gain
Add 300-500 calories above your activity level needs for gradual, healthy weight gain.
Factors Affecting BMR
Age, gender, weight, height, muscle mass, genetics, and thyroid function all influence your metabolic rate.
BMR Calculation Examples
Example 1: Active Male
Example 2: Active Female
Frequently Asked Questions
What's the difference between BMR and TDEE?
BMR is your resting metabolic rate, while TDEE (Total Daily Energy Expenditure) includes BMR plus calories burned through activity. Our calculator shows both BMR and TDEE estimates based on activity levels.
How accurate are BMR calculations?
The Mifflin-St Jeor equation used by our calculator is accurate within ±10% for most people. Individual variations exist due to genetics, muscle mass, and metabolic factors.
Should I eat below my BMR for weight loss?
Generally no. Eating significantly below BMR can slow metabolism and isn't sustainable. Create a moderate deficit from your total daily needs (activity level) instead.
How often should I recalculate my BMR?
Recalculate when you've lost or gained significant weight (5+ pounds), changed activity levels, or every few months to ensure accuracy.
Why do men have higher BMR than women?
Men typically have more muscle mass and less body fat, and muscle tissue burns more calories at rest. The calculation formulas account for these physiological differences.
What factors can increase or decrease BMR?
Muscle mass, thyroid function, genetics, age, and body composition affect BMR. Strength training can help maintain or increase BMR as you age.
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