About the TDEE and BMR Calculator
Your basal metabolic rate is the energy your body uses at complete rest to run your brain, heart, lungs and cell repair, and it accounts for most of what you burn in a day. Total daily energy expenditure adds movement, exercise and the energy cost of digesting food, and it is the number that actually determines whether you gain or lose weight. This calculator uses the Mifflin-St Jeor equation, which research has repeatedly found to be the most accurate of the simple formulas.
Multiplying by an activity factor is the weakest part of any TDEE estimate, because most people overestimate how active they are. If your weight is not moving in the direction you expect after two or three weeks, adjust the calories by 100 to 200 rather than assuming the formula is right. A deficit of 500 kcal a day corresponds to roughly half a kilogram of fat a week, and going much steeper tends to cost muscle and adherence.
How to use the TDEE and BMR Calculator
- Enter your sex, age, weight in kilograms and height in centimetres.
- Choose the activity level that honestly matches your week.
- Read your maintenance calories, then the target for losing or gaining weight.