FatCalc

TDEE Calculator

Use this TDEE calculator to find the total number of calories your body burns daily and your energy requirements. It's accurate for all age groups, including infants and toddlers. The calculator uses formulas developed by the Institute of Medicine of the National Academies.

TDEE Calculator

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For individuals with a healthy BMI (18.5 to 25), the calculator calculates Estimated Energy Requirement (EER). EER is the number of calories needed daily to balance out the body's expenditure of energy to maintain body size and composition at a level of physical activity consistent with long-term good health.

Consider TDEE as the energy needed to maintain your current weight. Knowing your TDEE will help you estimate the daily calorie intake you need to achieve a weight loss or weight gain goal. To lose weight, create a caloric deficit by eating fewer calories than your TDEE. In this way, you burn more energy than you take in, resulting in weight loss. To gain weight, create a calorie surplus by eating more calories than your TDEE.

To achieve a desirable lower steady-state body weight, overweight individuals need to intake fewer calories than their current TDEE. The desirable calorie intake for underweight individuals is greater than their current TDEE to permit weight gain.

Your Body's Energy Requirements

Your body constantly expends energy to perform physical activities and support its autonomic systems such as breathing, the nervous system, circulation, and body temperature regulation. Energy is also required to transport, synthesize and replace molecules that make up body tissue. The body breaks down chemical bonds in food through oxidization to get its energy. The elements that combine with oxygen produce carbon dioxide, water, and heat to maintain body temperature. Some energy gets captured into an intermediate chemical form known as ATP, the primary energy source for most cellular processes and is considered the body's "energy currency."

Fat, protein, and carbohydrates are the macronutrients that provide you with energy from foods. Carbohydrates and protein release about 4 kcal of energy per gram through oxidation, whereas fat releases about 9.4 kcal of energy per gram.

Your Body's Energy Expenditure Components

BMR (Basal Metabolic Rate)

Basal metabolic rate (BMR) is your body's rate of energy expenditure when food and physical activity have minimal influence on metabolism. It reflects the minimum energy needed to sustain metabolic processes that keep you alive. An accurate BMR measurement requires a specific setting, such as an overnight fast where the subject hasn't eaten for 12 to 14 hours, resting awake and motionless while lying on their back in a thermoneutral environment. To be more meaningful, BMR is usually extrapolated over 24 hours and then referred to as basal energy expenditure (BEE) and expressed as kcal per day.

The tools and equipment needed to measure BMR are not always readily accessible. However, BMR and BEE can be easily estimated using prediction equations based on body parameters such as weight, height, gender, and age. BMR is related to body size and most closely correlated with lean body mass, which is the total body weight minus the weight of its fat mass. Studies show that lean body mass accounts for about 73 percent of your BMR, with fat mass accounting for only an additional 2 percent. Thus, lean body mass is the single best predictor of RMR. Since the body composition of males and females differ, so will their respective BMR, even if they both have the same body size and are of the same age.

TEF (Thermic Effect of Food)

TEF (Thermic Effect of Food) is the energy required to digest, absorb, transport, metabolize, and store ingested nutrients. It accounts for a percentage of the body's total energy expenditure and depends on the amount and composition of the consumed food. Fats require the least energy to be processed, carbs are next in line, while protein requires the most. Consuming an average mixture of macros will elicit an additional total energy expenditure equivalent to an average of about 10 percent of the energy content of the food consumed.

TEPA (Thermic Effect of Physical Activity)

The most variable component of TDEE is the expenditure of energy from physical activity. It varies significantly among individuals. The Thermic Effect of Physical Activity typically accounts for 15 to 30% of daily calorie burn. It can rise to as much as one-half or more in very active individuals, heavy laborers, and athletes. TEPA includes the energy expended through structured exercises and non-exercise activity thermogenesis (NEAT). NEAT refers to the energy burned through typical daily living activities such as performing household tasks, walking to the bus, light activities while sitting, driving, shopping and fidgeting.

TDEE (Total Daily Energy Expenditure)

TDEE, Total Daily Energy Expenditure, consists of basal energy expenditure, food's thermic effect, and physical activity's thermic effect. For children, pregnant and lactating women, TDEE also includes the energy expenditures due to new tissue formed during growth and pregnancy and milk production during lactation.

Calculating TDEE

TDEE calculators typically rely on a BMR prediction formula and then factor in a physical activity level to arrive at a TDEE value. Standard BMR formulas used in the calculation include the Harris-Benedict equation, the Mifflin St-Jeor equation, and the Katch-McArdle formula.

Unlike other calculators, this one uses predictive equations developed by the Institute of Medicine of the National Academies derived from information on energy expenditure obtained through Doubly Labelled Water (DWL) studies. The advantage of the DLW method is that it can measure TDEE in free-living individuals, and it has become the gold standard in determining energy requirements under daily living conditions. The DWL method involves administering two stable isotopic forms of water to a subject and then measuring their disappearance rates from body fluid (urine or blood) over a 1 to 3-week period. The differences in their disappearance rate reflect the amount of carbon dioxide production. From this, and with knowledge of the diet composition, TDEE can be accurately determined.

The TDEE and EER Formulas Used

The calculator applies different formulas depending on the subject's age, gender, and weight status. The formulas accept age in years, weight in kilograms (kg), and height in meters (m).

The activity level categories for the PA (Physical Activity) coefficients are defined as follows:

  • Sedentary: Typical daily living activities such as household tasks, walking to the bus, light activities while sitting, driving, shopping.
  • Low Active: Typical daily living activities plus 30 to 60 minutes of moderate activities such as walking or cycling leisurely, golfing without a cart etc.
  • Active: Typical daily living activities plus at least 60 minutes of daily moderate activity. cycling (leisurely), golf (without cart), swimming (slow), walking 3-4mph, etc.
  • Very Active: Typical daily living activities plus at least 60 minutes of daily moderate activity plus an additional 60 minutes of vigorous activity or 120 minutes of moderate activity

The following EER (Estimated Energy Requirements) formulas apply to subjects in a normal weight range and infants and toddlers.

EER for Men Ages 19 Years and Older
EER = 662 – (9.53 x age) + PA x (15.91 x weight + 539.6 x height), where
PA = 1.00 (sedentary)
PA = 1.11 (low active)
PA = 1.25 (active)
PA = 1.48 (very active)
EER for Women Ages 19 Years and Older
EER = 354 – (6.91 x age) + PA x (9.36 x weight + 726 x height), where
PA = 1.00 (sedentary)
PA = 1.12 (low active)
PA = 1.27 (active)
PA = 1.45 (very active)
EER for Boys 3 Through 18 Years
EER = 88.5 – (61.9 x age) + PA x (26.7 x weight + 903 x height + K, where
PA = 1.00 (sedentary)
PA = 1.13 (low active)
PA = 1.26 (active)
PA = 1.42 (very active)
K = 20 for ages 3 through 8. K= 25 for ages 9 through 18
EER for Girls 3 Through 18 Years
EER = 135.3 – (30.8 x age) + PA x (10.0 x weight + 934 x height) + K, where
PA = 1.00 (sedentary)
PA = 1.16 (low active)
PA = 1.31 (active)
PA = 1.56 (very active)
K = 20 for ages 3 through 8. K= 25 for ages 9 through 18
EER for Ages 0 Through 36 Months
EER = TDEE + energy deposition
0–3 months (89 weight [kg] – 100) + 175 kcal
4–6 months (89 weight [kg] – 100) + 56 kcal
7–12 months (89 weight [kg] – 100) + 22 kcal
13–36 months (89 weight [kg] – 100) + 20 kcal

The following TDEE (Total Daily Energy Expenditure) formulas apply to overweight or obese subjects.

TDEE in Overweight and Obese Men Ages 19 Years and Older
TDEE = 864 – (9.72 x age) + PA x (14.2 x weight + 503 x height), where
PA = 1.00 (sedentary)
PA = 1.12 (low active)
PA = 1.27 (active)
PA = 1.54 (very active)
TDEE in Overweight and Obese Women Ages 19 Years and Older
TDEE = 387 – (7.31 x age) + PA x (10.9 x weight + 660.7 x height), where
PA = 1.00 (sedentary)
PA = 1.14 (low active)
PA = 1.27 (active)
PA = 1.45 (very active)
TDEE in Overweight Boys Ages 3 Through 18 Years
TDEE = 114 – (50.9 x age) + PA x (19.5 x weight + 1161.4 x height), where
PA = 1.00 (sedentary)
PA = 1.12 (low active)
PA = 1.24 (active)
PA = 1.45 (very active)
TDEE in Overweight Girls Ages 3 Through 18 Years
TDEE = 389 – (41.2 x age) + PA x (15.0 x weight + 701.6 x height), where
PA = 1.00 (sedentary)
PA = 1.18 (low active)
PA = 1.35 (active)
PA = 1.60 (very active)

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References

  1. Institute of Medicine. 2005. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press. https://doi.org/10.17226/10490
  2. Henry, C. (2005). Basal metabolic rate studies in humans: Measurement and development of new equations. Public Health Nutrition, 8(7a), 1133-1152. doi:10.1079/PHN2005801
  3. Westerterp KR. Doubly labelled water assessment of energy expenditure: principle, practice, and promise. Eur J Appl Physiol. 2017;117(7):1277-1285. doi:10.1007/s00421-017-3641-x