TDEE calculator
TDEE calculator
Total Daily Energy Expenditure — the calories you burn per day. Uses the Mifflin-St Jeor equation, the most accurate BMR formula in validation studies.
Resting metabolism (BMR): 1,787 kcal/day. Eat this to hold your weight; eat below it to lose.
On a GLP-1? Wegovy, Zepbound, and similar drugs work by lowering appetite, so you naturally eat below your TDEE without counting. This number is still useful: it tells you roughly how far below maintenance you already are, and it flags when your intake has dropped so low that muscle loss and fatigue become risks. Pair any deficit with a protein floor (see the macro calculator) and resistance training.
How TDEE is calculated
The calculator first estimates your Basal Metabolic Rate (BMR) — the calories your body uses at rest — with the Mifflin-St Jeor equation:
- Men: (10 × kg) + (6.25 × cm) − (5 × age) + 5
- Women: (10 × kg) + (6.25 × cm) − (5 × age) − 161
BMR is then multiplied by an activity factor (1.2 for sedentary up to 1.9 for extremely active) to give TDEE — your maintenance calories.
Using TDEE on a GLP-1 program
On semaglutide (Wegovy, Ozempic) or tirzepatide (Zepbound, Mounjaro), appetite suppression usually drops your intake below TDEE without conscious effort — that is the mechanism of the weight loss. The failure mode is the opposite of most diets: intake can fall so far that you lose muscle, feel exhausted, and stall. Use your TDEE to sanity-check that you are not more than ~750 kcal/day below maintenance for long stretches, and protect lean mass with adequate protein and resistance training. Compare programs on our GLP-1 comparison pages.
TDEE calculator FAQ
What is TDEE?+
TDEE (Total Daily Energy Expenditure) is the total number of calories you burn in a day — your resting metabolism (BMR) multiplied by an activity factor. Eating at your TDEE holds your weight steady; eating below it produces weight loss.
How accurate is this TDEE calculator?+
It uses the Mifflin-St Jeor equation, which outperformed Harris-Benedict and other formulas for predicting resting energy expenditure in validation studies. The activity multiplier is an estimate, so treat the result as a starting point and adjust based on 2-3 weeks of real weight data.
How does TDEE work with a GLP-1 like Wegovy or Zepbound?+
GLP-1 medications lower appetite, so most people naturally eat well below their TDEE without deliberate counting. Your TDEE still tells you how large that gap is and warns when intake has dropped so low that muscle loss and fatigue become risks. Aim to keep the deficit moderate and hit your protein target.
Should I eat back exercise calories?+
If you selected an activity level that already includes your exercise, no — it is baked into the multiplier. Only add calories back if you chose a lower activity level and then did an unusually hard session.
Source
Mifflin MD, St Jeor ST, Hill LA, et al. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247. PMID: 2305711.