Free online calculator to determine your Total Daily Energy Expenditure using the Mifflin-St Jeor Equation
This TDEE (Total Daily Energy Expenditure) calculator helps you determine the number of calories your body burns each day. Understanding your TDEE is essential for managing your weight, whether your goal is to lose fat, gain muscle, or maintain your current physique. By knowing your daily caloric needs, you can make informed decisions about your nutrition and create a sustainable eating plan tailored to your specific goals.
Our calculator uses a scientifically validated two-step process to determine your Total Daily Energy Expenditure:
We use the Mifflin-St. Jeor Equation, which is considered one of the most accurate formulas for estimating BMR. This equation was developed in 1990 and has been validated through numerous scientific studies. It takes into account your weight, height, age, and biological sex to estimate how many calories your body burns at complete rest.
Your BMR represents only the calories burned at rest. To get your Total Daily Energy Expenditure, we multiply your BMR by an activity factor that reflects your lifestyle and exercise habits:
The total number of calories your body burns in a 24-hour period, including all activities. This accounts for your basal metabolic rate plus all physical activity, from fidgeting to intense exercise. Your TDEE represents your maintenance calorie level - eating at this level will maintain your current weight.
The number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, cell production, and nutrient processing. This typically accounts for 60-75% of your total daily energy expenditure. Even while sleeping, your body requires energy to keep you alive.
A unit of energy. In nutrition, we typically refer to kilocalories (kcal), though they're commonly called "calories." One calorie is the amount of energy needed to raise the temperature of 1 kilogram of water by 1 degree Celsius. Approximately 3,500 calories equals one pound of body fat, meaning you need a deficit of 3,500 calories over a span of time to lose one pound of fat, or a surplus of 3,500 calories to gain one pound.
A numerical factor (ranging from 1.2 to 1.9) used to account for the calories burned through physical activity and daily movement. This multiplier is applied to your BMR to calculate your TDEE. The more active you are, the higher your multiplier and total calorie needs.
A mathematical formula developed in 1990 by researchers M.D. Mifflin and S.T. St Jeor. It's considered one of the most accurate methods for estimating resting metabolic rate in healthy adults. The American Dietetic Association recommends this equation for calculating BMR in clinical settings.
Citation: Mifflin, M. D., St Jeor, S. T., Hill, L. A., Scott, B. J., Daugherty, S. A., & Koh, Y. O. (1990). A new predictive equation for resting energy expenditure in healthy individuals. The American Journal of Clinical Nutrition, 51(2), 241-247. https://doi.org/10.1093/ajcn/51.2.241
The relationship between calories consumed (through food and drink) and calories expended (through BMR and activity). A caloric surplus (eating more than your TDEE) leads to weight gain, a caloric deficit (eating less than your TDEE) leads to weight loss, and eating at your TDEE maintains your current weight.