BMR Calculator: Basal Metabolic Rate Estimate

Free basal metabolic rate calculator

Basal metabolic rate is the estimated amount of energy your body uses at rest to support basic functions such as breathing, circulation, cell repair, and temperature regulation. BMR is the baseline behind many calorie calculators, but it is not the same as total daily calories.

This calculator uses the Mifflin-St Jeor equation. After BMR is estimated, you can use an activity multiplier or the calorie calculator to estimate TDEE.

Formula used

For metric inputs, the Mifflin-St Jeor equation uses weight in kilograms, height in centimeters, age in years, and sex-specific constants. The result is calories per day at rest.

Men: 10 × kg + 6.25 × cm − 5 × age + 5
Women: 10 × kg + 6.25 × cm − 5 × age − 161

How to use BMR

BMR is useful for understanding the resting part of your energy needs. Most adults burn more than BMR because walking, working, training, digestion, and daily tasks require energy. If you are planning food intake, TDEE is usually more useful than BMR alone.

Example

A 30-year-old male who weighs 180 lb and is 70 in tall may have a BMR around 1,800 calories per day. If he trains several times per week, his total daily calories could be much higher.

Frequently asked questions

Is BMR the same as maintenance calories?

No. BMR is resting calories. Maintenance calories usually require multiplying BMR by an activity factor.

Which formula is used?

This calculator uses the Mifflin-St Jeor equation, a commonly used adult BMR equation.

Why does sex affect the result?

The equation accounts for average differences in body size and body composition.

Can BMR change?

Yes. BMR can change with weight, age, muscle mass, dieting history, illness, hormones, pregnancy, and medication.

Should I eat below BMR?

Do not use BMR as a diet target without professional guidance. Very low calorie intake can be risky for some people.