BMR Calculator

What is Basal Metabolic Rate?

Your Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest just to keep vital functions running — breathing, circulation, cell repair and keeping you warm. It typically accounts for the majority of the calories you use each day, before any movement or exercise is added.

How BMR is calculated

This calculator uses the Mifflin-St Jeor equation, one of the most accurate formulas in everyday use. It combines your sex, age, weight and height, since men, younger people and larger or taller bodies generally have a higher metabolic rate. The result is your daily calorie burn at rest.

How to use this calculator

Select your sex and enter your age, weight and height, then press Calculate to see your BMR in calories per day. To estimate the calories you actually need, multiply this figure by an activity factor — from about 1.2 if you are sedentary up to 1.9 if you are very active.

Why BMR matters

Knowing your BMR is the foundation of managing your weight: it tells you the minimum energy your body requires, so you rarely want to eat below it for long. Use it together with your activity level to set realistic calorie targets for losing, maintaining or gaining weight.