Jump to: Energy Expenditure Calculator
Knowing a little bit about your energy expenditure and approximate metabolic rate can help give you a picture of about how much you should be eating in a day. You don’t have to count the calories you eat and use every day, but it can help to count them periodically to see if you’re approximately “on the right track.”
Your energy expenditure is simply the number of calories your body uses. Your total daily energy expenditure (TDEE) is the number of calories your body uses in one day. A large component of whether you lose or gain weight is related to the balance between your food intake (“calories in”) and energy expenditure (“calories out”).
There are 3 main components that make up your energy expenditure:
1. Basal metabolic rate (BMR) reflects the calories your body uses to keep itself running. This is essentially the number of calories you use by “doing nothing.” BMR accounts for ~55-60% of energy expenditure . BMR is about 10% lower than the resting metabolic rate (RMR), which is measured under less strict conditions.
2. The thermic effect of food (TEF) is the energy used to process food that has been eaten. The amount of calories used to process the food is approximately equal to 10% of the calories eaten (e.g. – 250 calories if you consume 2500 calories per day) *. TEF accounts for ~10-15% of energy expenditure.
3. Physical activity is the most variable of the three components. While the standard contribution to energy expenditure is designated at ~20-30%, it can range from very low values in sedentary individuals to higher values in very active individuals .
You can use the calculator below to find out your approximate daily energy expenditure**.
It is important to remember that this TDEE equation provides an estimate of your caloric expenditure and caloric needs. While the calculator is a convenient tool, it is not perfectly accurate.
With that said, if your TDEE and your caloric intake are equal, you should maintain a relatively stable weight. If your TDEE exceeds your caloric intake, you may lose weight. If your caloric intake exceeds your TDEE, you may gain weight. While there are other factors involved (eg – the amount of protein, carbohydrate, and fat in your diet, your percent body fat, etc.), this is a good starting point for understanding your energy balance.
The activity levels are used in the calculation are approximations, and some individuals may need even fewer calories than “Sedentary” or even more calories than “Very active.” If you feel “in between” two categories, you can try selecting each one and use a TDEE that falls between them.
Notes and References
*While 10% is the textbook value for the energy used while consuming a mixed diet, the specific macronutrient composition of the diet also plays a large role. Protein raises energy expenditure the most (~20-30%), carbohydrates have an intermediate effect (~5-10%), and fats raise energy expenditure the least (~0-5%) . The range for how much TEF can increase energy expenditure ranges from approximately 5-30%.
**This calculator doesn’t factor in TEF as its own component. Since RMR is ~10% greater than BMR and the TEF is ~10%, they approximately “cancel out” . So, to get your total energy expenditure, you simply need to multiply your RMR by your activity level (as is done in the calculator).
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