BMR Calculator
Estimate how many calories your body uses at complete rest.
For information only. This calculator gives a general estimate from a standard formula and is not medical advice. It doesn't account for factors such as muscle mass, pregnancy, age-related changes or health conditions. Talk to a doctor or registered dietitian about your health.
How it works
- Choose your units and sex.
- Enter your age, height and weight.
- Read your estimated basal metabolic rate in calories per day.
Frequently asked questions
What is BMR?
Basal metabolic rate is the energy your body uses at complete rest to keep you alive — breathing, circulation and cell repair. It is usually 60–75% of the calories you burn in a day.
Which formula does this use?
The Mifflin-St Jeor equation, which research has found to be the most accurate simple formula for most adults: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for men, or − 161 for women.
How do I get total daily calories from BMR?
Multiply BMR by an activity factor, or use the Calorie Calculator, which does this and shows targets for losing or gaining weight.
Why is my real metabolism different?
Muscle mass, genetics, hormones and health conditions all affect metabolism. Treat the result as a starting estimate.
Your body's baseline energy use
Your basal metabolic rate is the number of calories you'd burn lying still all day. Knowing it helps you plan nutrition, because everything else — walking, working, exercising — is added on top.
Why the Mifflin-St Jeor equation
Several BMR formulas exist. Studies comparing them with measured metabolism found Mifflin-St Jeor (1990) to be the most reliable for the general adult population, so it's the formula used here.