Free daily calorie calculator
Find the calories your day asks for.
Compare three established formulas. No account, no email, no manufactured precision.
For adults. A planning estimate, not medical advice.
The short answer
What is TDEE?
TDEE means total daily energy expenditure: an estimate of all the energy your body uses in 24 hours. It combines resting energy, digestion, exercise, and ordinary movement such as walking or standing.
A calculator first estimates resting energy, then multiplies it by an activity factor. The result is the approximate calorie intake at which your body weight may remain stable. Real expenditure changes from day to day, which is why the trend you observe over time matters more than a perfectly tidy number.
Method, made visible
Why show three formulas?
Resting energy cannot be read directly from height and weight. Each formula is a model built from a different group of people, so comparison is more honest than pretending one estimate is exact.
01
Mifflin–St Jeor
10 × kg + 6.25 × cm − 5 × age + coefficient
Uses weight, height, age, and a sex-specific coefficient. Countwell makes this the primary estimate because it is a practical modern starting point for the general adult population.
02
Revised Harris–Benedict
Revised weight, height, age & sex coefficients
Also uses weight, height, age, and sex, but applies coefficients from the 1984 reevaluation of the original Harris–Benedict work. It is useful as a second view, not a competing truth.
03
Katch–McArdle
370 + 21.6 × lean mass in kg
Uses estimated lean body mass instead of sex-specific coefficients. It only appears when you enter body fat, and it is only as useful as that body-fat estimate.
Questions, answered
TDEE calculator FAQ
What is TDEE?
Total daily energy expenditure is the energy your body uses across a full day. It includes resting energy, the energy used to digest food, and energy used through exercise and everyday movement.
Which TDEE formula should I use?
Mifflin–St Jeor is a sensible general starting point for adults, so Countwell uses it for the primary result. Revised Harris–Benedict provides a useful comparison. Katch–McArdle can add context when you have a reasonably accurate body-fat estimate because it uses lean body mass.
How accurate is a TDEE calculator?
It is an estimate, not a measurement. Formula choice, activity selection, body composition, and normal differences between people can all shift the result. Use the number as a starting point, then compare it with your average intake and weight trend over two to three weeks.
What activity level should I choose?
Choose the level that best describes your whole week, including work and everyday movement—not only workouts. If you sit most of the day and train a few times per week, lightly or moderately active is usually a more honest starting point than very active.
Is TDEE the same as BMR?
No. BMR estimates the energy required at complete rest. TDEE starts with a resting estimate and accounts for activity across the day, so it is higher for nearly everyone.
Does Countwell save my calculator data?
No. This calculator runs in your browser and does not save or send the measurements you enter. If you later choose to build a Countwell plan, that is a separate action.
Sources: the original Mifflin–St Jeor study, the 1984 Harris–Benedict reevaluation, and the National Academies review of energy expenditure.