How to Calculate TDEE, Resting Energy and Activity Calories

A calorie calculator can answer two different questions: how much energy an adult might use during a whole day, or how much energy a particular activity might use. These estimates are related, but they are not interchangeable. Adding an activity result to a daily estimate without checking the assumptions can count the same activity twice.

The Calorie Calculator: TDEE, Resting Energy & Activity separates these tasks. It provides an educational estimate rather than a measured metabolism, a prescribed food intake or a prediction of weight change. Food-label Calories refer to kilocalories, abbreviated kcal.

BMR vs RMR: estimate resting energy first

Daily mode starts with the Mifflin-St Jeor equation for resting energy expenditure. In metric units, it is 10 x weight in kilograms + 6.25 x height in centimeters - 5 x age + a coefficient. The published male coefficient is +5; the female coefficient is -161.

This equation estimates resting metabolic rate, or RMR. Basal metabolic rate (BMR) describes expenditure under stricter basal measurement conditions. The terms are often interchanged online, but this tool does not measure either. Its coefficients come from population data and cannot capture every individual's body composition, health circumstances or energy expenditure.

For a 30-year-old adult with a weight of 70 kg, a height of 175 cm and the male coefficient, the calculation is 700 + 1093.75 - 150 + 5 = 1648.75 kcal per day at rest.

How to calculate your TDEE

To estimate total daily energy expenditure (TDEE), multiply estimated resting energy by a daily activity factor. With the example above and a factor of 1.20, the result is 1648.75 x 1.20 = 1978.5 kcal per day, displayed as 1979.

The factor is an assumption about the whole day, not a personalized measurement. The default 1.20 represents a rough low-activity scenario. The calculator allows you to change it, but it cannot determine the correct factor from your occupation, fitness level or exercise history.

Resting energy, total daily energy expenditure and appropriate food intake are different concepts. A qualified professional can help interpret needs that these equations do not address. This tool does not automatically subtract calories to create a weight-loss target.

TDEE estimates for women and men

The selected equation coefficient changes the resting estimate. For the same age, weight, height and factor above, the female coefficient gives 1482.75 kcal/day at rest and 1779.3 kcal/day estimated TDEE. This is a population-based calculation, not an individual metabolic test.

Calculate energy for one activity

Activity mode uses duration, body weight and an activity intensity expressed in metabolic equivalents, or METs. Select a documented MET value matching the specific activity and intensity. The Compendium of Physical Activities provides reference descriptions; a general activity name alone may not identify the right intensity.

The gross estimate is MET x 3.5 x weight in kilograms / 200 x minutes. For 70 kg, 30 minutes and 3.5 MET, this equals 128.625 kcal, displayed as 129. The MET value in this example illustrates the arithmetic rather than prescribing an activity.

Distinguish gross from additional energy

Gross activity energy includes the conventional resting component during that period. Replacing MET with MET - 1 estimates energy above the one-MET reference. In the example, 2.5 x 3.5 x 70 / 200 x 30 = 91.875 kcal, displayed as 92.

One MET is a standardized reference, not a direct measurement of your resting metabolism. Neither the gross nor the additional estimate should be added automatically to daily maintenance energy. Your daily activity factor may already include that session.

Enter consistent units and check the scope

Metric mode uses kilograms and centimeters. US mode uses pounds, whole feet and additional inches. The tool converts with 1 lb = 0.45359237 kg and 1 inch = 2.54 cm. Changing units clears measurement fields to reduce accidental unit mismatches.

Daily mode supports ages 20 to 78. The original resting-energy study included ages 19 to 78, and this calculator adopts a narrower adult scope. It is not intended for children, pregnancy, breastfeeding or clinical nutrition planning. Its input limits are software boundaries, not recommended weights, heights or exercise levels.

If you already have a chosen calorie total and macro percentages, the Macro Calculator converts them into grams. It does not select an appropriate intake or split.

Sources and handling your information

See Mifflin et al., 1990 for the resting-energy equation and the Compendium of Physical Activities for activity references. Results are rounded only for display. The calculator runs locally without saving or transmitting entries; the hosting website may separately use analytics or other services under its privacy policy.