The BMR Calculator estimates your Basal Metabolic Rate — the number of calories your body needs at complete rest to keep essential functions running, such as breathing, circulation, brain activity and cell repair. For most people, BMR is the largest single part of daily energy use (around 60–70%).

How it is calculated

This tool uses the Mifflin–St Jeor equation, the formula most recommended by dietitians today, and also shows the older Revised Harris–Benedict estimate for comparison. Both use your age, gender, height and weight. BMR tends to be higher for people who are taller, heavier, younger or more muscular, and is usually higher for men than women of the same size.

BMR vs TDEE

Your TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor. It represents the calories you actually burn on a typical day once movement and exercise are included. Eating around your TDEE keeps your weight steady; eating below it leads to weight loss and above it to weight gain.

A guide, not medical advice

These figures are estimates for healthy adults and are not suitable for pregnancy, serious illness or eating-disorder recovery; children and teens have different needs. For anything important, talk to a doctor or registered dietitian. Nothing you enter is uploaded — the calculation runs entirely in your browser.