Basal Metabolic Rate is the number of calories your body needs to perform basic life-sustaining functions like breathing and circulation while at complete rest.

Why does BMR differ between men and women?

Men typically carry more lean muscle mass than women at the same weight, and muscle burns more calories at rest than fat, so the formula adds a small adjustment for sex.

How is BMR different from TDEE?

BMR is calories burned at complete rest. TDEE (Total Daily Energy Expenditure) multiplies BMR by an activity factor to estimate the calories you burn in a typical day.

Health & Fitness

BMR Calculator

Enter your sex, age, height, and weight to estimate your Basal Metabolic Rate — the number of calories your body burns just to stay alive at rest.

Your calculation is performed in your browser.

Fill in your details above to estimate your BMR.

This result is an estimate for informational and educational purposes. It isn’t a diagnosis and isn’t a substitute for advice from a doctor, registered dietitian, or other qualified professional. See our methodology and sources for the formula used and its limitations.

How it works

The calculator uses the Mifflin-St Jeor equation, widely regarded as one of the most accurate BMR formulas for the general population, combining your weight, height, age, and sex into a single resting-calorie estimate.

Formula & methodology

The Mifflin-St Jeor equation is used. It is widely regarded as one of the more accurate ways to estimate the calories your body burns at complete rest. Results are rounded to the nearest whole calorie.

MenBMR = (10 × weight) + (6.25 × height) − (5 × age) + 5

WomenBMR = (10 × weight) + (6.25 × height) − (5 × age) − 161

What each term means

Weight: Body weight in kilograms.
Height: Height in centimetres.
Age: Age in years.
BMR: Basal metabolic rate, in calories per day.

Worked example

A 30-year-old woman who is 165 cm tall and weighs 65 kg has an estimated BMR of about 1,370 calories per day.

Common uses

—Establishing a baseline resting-calorie number before calculating TDEE or a calorie target.
—Understanding how age, sex, height, and weight affect your body’s baseline energy needs.
—Comparing your resting metabolism against activity-based calorie burn.

Important notes

—BMR assumes complete rest — it does not include calories burned through daily activity or exercise.
—To find your total daily calorie needs, use the TDEE Calculator, which applies an activity multiplier to your BMR.