BMR calculator (basal metabolic rate)
Calculate your basal metabolic rate (BMR) with the Mifflin-St Jeor, Harris-Benedict and Katch-McArdle formulas, and your daily calorie needs.
Basal metabolic rate calculator
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BMR calculator (basal metabolic rate): what it is for
Enter sex, age, weight and height to calculate how many calories your body burns at rest. The calculator compares three formulas and, with your body fat percentage, also uses Katch-McArdle, based on lean mass.
You also see your daily calorie needs for each activity level, from sedentary to athlete.
How to use
- Fill in sex, age, weight and height.
- Enter body fat if you know it.
- See your BMR and daily calorie needs.
When to use it
- Plan a diet to lose weight or gain muscle.
- Understand your own energy use.
- Compare metabolism formulas.
Frequently asked questions
What is the basal metabolic rate?
It is the number of calories your body burns at complete rest to keep vital functions going, like breathing, circulation and temperature. It is the largest part of daily energy use.
Which formula is most accurate?
Mifflin-St Jeor is the most recommended for most people. Katch-McArdle is better for people who know their body fat percentage, because it uses lean mass.
Is it really free?
Yes, 100% free. No sign-up, no subscription and no usage limits. All Tools123 tools are free and run right in your browser.