TDEE Calculator

Your Total Daily Energy Expenditure (TDEE) is an estimate of how many calories you burn in a typical day — everything from your resting metabolism to walking, working, and exercising. It is the number that matters most for managing your weight: eat roughly at your TDEE to maintain, below it to lose, and above it to gain.

TDEE is built in two steps. First we estimate your Basal Metabolic Rate (BMR) — the energy your body uses at complete rest to run essential functions like breathing, circulation, and temperature regulation. Then we multiply that by an activity factor that reflects how much you move during the day. The activity factor is the biggest source of uncertainty, because most people over- or under-estimate how active they really are.

Treat the number as a well-informed starting point rather than a precise measurement. Individual metabolism varies by roughly ±10–15% for reasons the formula can't see — body composition, genetics, hormones, sleep, and non-exercise movement. The most reliable approach is to eat at your estimated target for two to three weeks, track how your weight actually responds, and adjust from there.

The estimate is most reliable for healthy adults of typical body composition who can honestly place themselves in an activity category. For this group Mifflin-St Jeor predicts resting energy expenditure well, and the main task is simply choosing the right activity multiplier.

It is least accurate for people at the edges: those with very high muscle mass or very high body fat (BMR scales with lean mass, which the equation only estimates from total weight), people recovering from illness, and anyone whose activity varies a lot day to day. The activity multiplier is the biggest source of error for everyone — most people overestimate how active they are — so if the number doesn't match your real-world results after a couple of weeks, adjust the multiplier down a step before changing anything else.

Formula. We use the Mifflin-St Jeor equation for BMR: for men, BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5; for women, the same with − 161 instead of + 5. TDEE is then BMR × your activity multiplier (1.2 sedentary, 1.375 lightly active, 1.55 moderately active, 1.725 very active, 1.9 extremely active).

Why Mifflin-St Jeor. The Academy of Nutrition and Dietetics recommends Mifflin-St Jeor as the most accurate predictive equation for the general population, which is why it has largely superseded the older Harris-Benedict equation. It was validated against measured resting energy expenditure in healthy adults across a wide range of body sizes.

Confidence. We label TDEE moderate confidence. The equation itself is well validated, but the activity multiplier is a broad category rather than a personal measurement, and real metabolism varies from person to person — so the result is a reliable estimate to plan around, not an exact calorie count.