What is a BMR Calculator?
A BMR Calculator estimates your basal metabolic rate: the calories your body uses at complete rest for basic functions like breathing and circulation.
BMR depends on your sex, age, weight and height. This tool uses the Mifflin–St Jeor equation, which is widely used by dietitians. To include daily activity, use the TDEE Calculator.
How to use the BMR Calculator
- Select sex.
- Enter age.
- Enter weight.
- Enter height.
- Tap Calculate to see the result.
- Tap Reset to clear the fields and try again.
Who should use it
- People planning a diet
- Fitness beginners learning their calorie needs
- Anyone tracking weight changes
Key terms
- BMR
- Calories burned at rest in a day.
- Mifflin–St Jeor
- A standard equation for estimating BMR.
Frequently asked questions
Is BMR the same as daily calories?
No. Daily needs are higher because of movement and exercise.
Does muscle affect BMR?
Yes. More muscle usually means a higher BMR.
Does BMR drop with age?
Generally yes, slowly.
Is this medical advice?
No. Consult a doctor or dietitian.
Is my data stored?
No. Everything you enter stays in your browser and is cleared when you close the page.
Last updated: 1 November 2026