The Calorie Calculator estimates how many calories your body uses in a day and how many you should eat to reach a weight goal. It uses the widely trusted Mifflin–St Jeor equation, the same method used by dietitians.

BMR and TDEE

Your BMR (Basal Metabolic Rate) is the energy your body burns at complete rest — just to keep your heart, lungs and brain running. Your TDEE (Total Daily Energy Expenditure) is your BMR multiplied by an activity factor, and it represents the calories you burn on a typical day. Eating at your TDEE keeps your weight steady.

Losing or gaining weight

To lose weight you eat a little below your TDEE (a calorie deficit); to gain weight you eat a little above it (a surplus). A deficit or surplus of about 500 kcal a day changes your weight by roughly 0.5 kg (about 1 lb) a week. Slow and steady is easier to keep up and protects muscle.

Macros

The macro breakdown splits your target calories into protein, carbohydrate and fat. Protein is especially important when losing weight (it keeps you full and protects muscle) and when gaining (it helps build muscle rather than fat).

A guide, not medical advice

These numbers are estimates for healthy adults. They are not suitable for pregnancy, serious illness, or eating-disorder recovery, and 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.