Calculator
BMR Calculator
Estimate your Basal Metabolic Rate — the energy your body burns at complete rest — using the Mifflin-St Jeor equation.
BMR Calculator
Enter your details to estimate your BMR.
This tool is for education and general interest only. It is not a medical device and must not be used to diagnose, treat or make health decisions. Always consult a qualified professional.
How to use it
- Step 1Select your sex and enter your age.
- Step 2Enter your height and weight.
- Step 3Read your estimated BMR.
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body uses just to stay alive at rest — powering your heart, brain, breathing and temperature.
It is the largest part of most people's daily energy use, often 60–70% of the total.
The Mifflin-St Jeor equation
This tool uses the Mifflin-St Jeor equation, widely regarded as one of the most reliable simple estimates. It uses your weight, height, age and sex.
To estimate your full daily needs including movement, use the daily calorie estimator. Understand the biology in our metabolism guide.
Questions & Answers
Frequently asked questions
BMR is energy used at rest. Total daily energy adds the calories you burn through movement and digestion.
Muscle mass tends to decline with age, and muscle burns more energy than fat, so resting energy use gradually falls.
No. It is an educational estimate. For personal nutrition or weight goals, consult a qualified professional.
Understand the science
Go beyond the numbers
Every tool pairs with a guide that explains the biology behind it in plain language.