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Key Features
Instant Calculation
Get accurate results in real time with our optimized algorithm.
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Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to maintain basic functions — breathing, circulation, cell production. It's the foundation for any calorie-planning decision, whether for weight loss, maintenance, or gain.
This calculator uses the Mifflin-St Jeor equation — widely considered more accurate than the older Harris-Benedict formula for most adults — to estimate your BMR from your weight, height, age, and sex.
How it works
Enter your weight in kilograms, height in centimeters, age, and sex. The tool applies the Mifflin-St Jeor equation, which differs slightly between men and women, to estimate your daily resting calorie burn.
- Enter weight (kg).
- Enter height (cm).
- Enter age.
- Enter sex.
- Click Calculate to see your results.
Examples
Estimating BMR for a 30-year-old male
A 70kg, 175cm, 30-year-old male has an estimated BMR of about 1,649 kcal/day.
Who should use it
- Establishing a baseline for calorie planning or weight management.
- Understanding how much energy your body needs just to function at rest.
Industry applications
- Nutrition and dietetics
- Fitness and personal training
Advantages
- Uses the modern, widely-recommended Mifflin-St Jeor equation.
- Accounts for sex-specific differences in metabolism.
Limitations
- Doesn't include activity level — this is resting metabolic rate only.
- Formula-based estimates can't account for individual metabolic variation exactly.
Common mistakes to avoid
- Confusing BMR with total daily calorie needs, which also factor in activity level.
- Using BMR alone to set a calorie target without accounting for activity.
Best practices
- Use BMR as a starting point, then add an activity multiplier separately to estimate total daily calorie needs.
Tips
- Multiply your BMR by an activity factor (1.2 for sedentary, up to 1.9 for very active) to estimate your total daily calorie needs.