BMR calculator
The calories your body burns at complete rest, by three well-known formulas.
- 100% free
- No sign-up
- Runs in your browser
How to use BMR calculator
- Enter your details
- Add body fat if you know it
- Compare the results
About you
Sex
Your basal metabolic rate
Enter your age, height and weight to see your BMR.
Next: Calorie calculator · Body fat calculator · BMI calculator
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How to use BMR calculator
Enter your details
Choose your sex and type your age, height and weight in metric or imperial units.
Add body fat if you know it
Optional: type your body fat percentage to add the Katch-McArdle result, which works from lean mass.
Compare the results
See your BMR from each formula in kcal a day, plus your daily calories at five activity levels.
Why use Utils365
Three formulas
Mifflin-St Jeor, the revised Harris-Benedict and Katch-McArdle, so you can see how close they agree.
Daily totals too
A table multiplies your BMR by the standard activity factors, from sedentary to extra active.
Metric or imperial
Use cm and kg or feet, inches and pounds; the choice is remembered for next time.
Private
Everything is worked out in your browser. Nothing you type is sent or saved.
Frequently asked questions
What is BMR?
Basal metabolic rate: the energy your body uses at complete rest to breathe, pump blood and keep warm. For most people it’s 60 to 70% of all the calories they burn in a day.
How is BMR calculated?
Mifflin-St Jeor uses 10 × weight in kg + 6.25 × height in cm − 5 × age, then adds 5 for men or takes off 161 for women. A man of 30, 80 kg and 180 cm gets 1,780 kcal a day.
Which BMR formula is most accurate?
Studies find Mifflin-St Jeor the most reliable for most adults, usually within 10% of a measured value. Katch-McArdle can be better for lean, muscular people if you know your body fat.
What is the difference between BMR and TDEE?
BMR is what you burn lying still. TDEE adds everything else you do. Multiply BMR by 1.2 if you’re sedentary, up to 1.9 if you’re very active.
Does BMR go down with age?
Yes, mainly because muscle mass falls. In the Mifflin formula each extra year takes 5 kcal off, so ten years lowers BMR by 50 kcal a day.
How can I raise my BMR?
Building muscle helps most, since muscle burns more at rest than fat. Eating enough protein and not cutting calories too hard also keep it from dropping.