TDEE Calculator
Your TDEE — total daily energy expenditure — is roughly how many calories you burn in a day. Knowing it turns weight loss from guesswork into a number you can work with.
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What TDEE means
Your total daily energy expenditure (TDEE) is the number of calories your body uses in a day — your resting metabolism plus everything you do. This calculator estimates it with the well-established Mifflin–St Jeor equation (which gives your resting BMR) multiplied by an activity factor. Eat around your TDEE and weight holds steady; eat below it and you lose.
Using TDEE with a GLP-1
GLP-1 medications work by making it easier to eat less, so knowing your maintenance number helps you see whether your intake is actually in a deficit. It also helps you eat enough — under-eating on a GLP-1 can cost you muscle and energy, so pair your calorie target with a protein goal and see our guide on what to eat on a GLP-1.
Frequently asked questions
What is TDEE?
TDEE is your estimated total calories burned per day — resting metabolism plus activity. Eating at it maintains weight; below it, you lose.
How is TDEE calculated?
It uses the Mifflin–St Jeor equation for resting metabolism, times an activity factor (1.2–1.9). It's an estimate, not a lab measurement.
How many calories should I eat to lose weight?
A ~500/day deficit below TDEE is a common start (~1 lb/week). Don't go below ~1,200 (women) or ~1,500 (men) cal/day without medical guidance.
Is the TDEE number exact?
No — it's an estimate. Use it as a starting point and adjust based on your real weight trend over a few weeks.
Sources & further reading
- Mifflin MD, St Jeor ST, et al. — A new predictive equation for resting energy expenditure (the Mifflin–St Jeor equation).
- Academy of Nutrition and Dietetics — energy needs and safe rates of weight loss.