Free Calorie Calculator - Daily Calories, BMR & TDEE

Calorie Calculator

This calorie calculator estimates how many calories your body uses in a day and shows target intakes for losing, maintaining, or gaining weight. It first finds your basal metabolic rate (BMR) with the Mifflin-St Jeor equation, then multiplies it by an activity factor to give your total daily energy expenditure (TDEE) in kilocalories.

How the calculation works

BMR is the energy you burn at complete rest. The Mifflin-St Jeor equation uses weight, height, age, and sex, with different constants for men and women. Your TDEE is that BMR multiplied by one of five activity factors, from sedentary (1.2) to extra active (1.9). The weight-goal figures come straight from TDEE: a daily deficit of about 500 kcal is close to 0.45 kg of fat per week, because a kilogram of body fat stores roughly 7,700 kcal.

BMR (men)   = 10 × weight(kg) + 6.25 × height(cm) - 5 × age + 5
BMR (women) = 10 × weight(kg) + 6.25 × height(cm) - 5 × age - 161
TDEE = BMR × activity factor

Worked example

Take a 30-year-old man who is 180 cm and 80 kg. His BMR is 10 × 80 + 6.25 × 180 - 5 × 30 + 5 = 1,780 kcal. At a moderately active level (1.55) his maintenance intake is 1,780 × 1.55 = 2,759 kcal per day. To lose weight he would target about 2,259 kcal, a 500 kcal deficit, and to gain slowly about 3,009 kcal.

Activity levels and daily calories

The five activity factors below all use the same 1,780 kcal BMR, so you can see how movement changes the daily total.

These numbers are estimates for general information, not medical advice. Speak to a doctor or dietitian before starting a weight-loss or weight-gain plan.