How TDEE is estimated
The calculator starts with your basal metabolic rate (BMR) from the Mifflin–St Jeor equation, which uses weight, height, age and sex to estimate the energy your body burns at complete rest.
It then multiplies that BMR by an activity factor — a number from about 1.2 for a sedentary lifestyle up to 1.9 for very heavy daily training — to capture the extra calories you burn moving around and exercising. The result is your total daily energy expenditure.
Reading BMR versus TDEE
BMR is the floor: the calories needed just to keep your organs running. TDEE is always higher because it includes everything else you do in a day. The bar chart puts the two side by side so you can see how much of your daily burn comes from activity rather than basic metabolism.
Eating at your TDEE tends to hold weight steady. Eating consistently below it leads to weight loss, and above it to gain.
Tips for accuracy
An activity multiplier is a broad estimate, so refine your number with real data:
- Be honest about your activity level — most people overestimate it.
- Use TDEE as a baseline, then track weight over a few weeks to confirm it.
- A desk job with occasional gym sessions is usually "light", not "moderate".
- Recalculate as your weight changes, since BMR shifts with body size.
Health disclaimer
TDEE figures are estimates for general guidance, not medical advice. Individual metabolism varies, and equations cannot capture every factor. Consult a doctor or registered dietitian before making significant changes to your eating, especially if you have a health condition or are pregnant.
Formula
TDEE = BMR · activity factorFrequently asked questions
- What is the difference between BMR and TDEE?
- BMR is the energy your body uses at complete rest. TDEE adds the calories burned through daily activity and exercise, so it is always higher than BMR.