TDEE Calculator

Use this TDEE calculator to determine how many calories your body burns daily. It works for all ages, including young children. The calculator uses the latest Institute of Medicine of the National Academies formulas, as explained in their Dietary Reference Intakes (DRI) report.

What is Your TDEE?

TDEE stands for Total Daily Energy Expenditure. It is the energy your body uses daily and shows how many calories you need to maintain your current weight. If you eat fewer calories than your TDEE, you will lose weight. If you eat more calories than your TDEE, you will gain weight.

Your body needs energy to keep essential functions running, like breathing, the nervous system, blood flow, controlling body temperature, and physical movements. Energy is also needed to move, create, and replace the molecules that comprise your body tissues. The body gets this energy by breaking down the chemical bonds in the food you eat through oxidation.

The three primary nutrients that give your body energy from food are carbohydrates, protein, and fat. Carbohydrates and proteins provide about four calories per gram, while fat provides about nine calories per gram.

When you consume the same number of calories as you burn (your TDEE), your weight will remain stable because you are in a state of "energy balance." Suppose you eat more calories than your TDEE. In that case, your body will store the excess calories as fat, leading to weight gain, referred to as a "positive energy balance." On the other hand, if you consume fewer calories than your TDEE, your body will use stored fat for energy, resulting in weight loss due to a "negative energy balance."

Measuring and Calculating Energy Expenditure

You can find several online tools to calculate your Total Daily Energy Expenditure (TDEE). These tools use formulas to estimate your Basal Metabolic Rate (BMR), Resting Metabolic Rate (RMR), or Resting Energy Expenditure (REE). They then use a multiplication factor based on your activity level to calculate your TDEE. The estimates rely on your height, weight, sex, and age. Well-known equations include the updated Harris-Benedict formula, the Mifflin St-Jeor equation, and the Katch-McArdle formula. These formulas are based on energy expenditure data collected from people in the general population. Researchers gather this data using indirect calorimetry, which measures a person's oxygen use and carbon dioxide output in controlled lab settings to calculate energy expenditure.

Unlike other TDEE calculators, this calculator uses the newest formulas created by the Institute of Medicine of the National Academies. The formulas are based on energy expenditure studies using Doubly Labelled Water (DWL). DLW measurements are now considered one of the best ways to determine a person's total daily energy expenditure (TDEE). They work well because they measure people's energy expenditure while going about their daily lives without restrictions. Unlike indirect calorimetry, DLW studies observe energy use in real-life situations instead of in a controlled lab setting.

The DLW method involves having individuals drink two stable water isotopes and measuring how quickly these isotopes leave the body through fluids such as urine or blood throughout 1 to 3 weeks. The varying rates of disappearance indicate the amount of carbon dioxide the body produces. TDEE can be accurately determined by analyzing these rates and considering the composition of the individual's diet.

Estimated Energy Requirement (EER)

According to the Dietary Reference Intakes report, the Estimated Energy Requirement (EER) is the calories needed to sustain overall well-being. Thus, this calculator computes and presents energy usage based on EER, not TDEE, for individuals with an average weight. The EER prediction formulas apply to:

1. Adults who are considered to have a healthy weight based on their BMI (Body Mass Index) falling between 18.5 and 25.
2. Children between the ages of 3 and 18 who fall within the 5th and 85th percentile for BMI.
3. Infants and toddlers aged up to 2 years who fall within the 3rd and 97th percentile for BMI.

If you are overweight and want to lose weight, start by finding your Total Daily Energy Expenditure (TDEE). You can calculate your TDEE using the DRI formulas in this calculator. This number will help you set a realistic weight loss goal. To lose weight, you must eat fewer calories than your current TDEE. A good starting point is to eat 200 fewer calories each day than your TDEE. Remember, as you lose weight, your TDEE will also go down. It's essential to check your TDEE regularly during your weight loss journey to keep your calorie intake lower than this number.