What TDEE is
Your Total Daily Energy Expenditure is the calories you burn in a day: your resting burn (BMR) — what your body uses just to keep running — plus everything you do on top, from walking to the shops to a hard training session. It is your maintenance line: eat around it and your weight holds steady.
Why a range, not a number
Every TDEE starts with a BMR estimate, and the published equations disagree — Mifflin–St Jeor, the two Harris–Benedict versions, WHO/FAO and Katch–McArdle can land a couple of hundred calories apart for the same person. Then the activity multiplier is a broad bracket, not a measurement. A single tidy figure hides all of that. We run five formulas and show the spread, so you read the uncertainty instead of trusting a false decimal.
The activity multiplier
BMR is multiplied by an activity factor — roughly 1.2 (sedentary) up to 1.9 (very physical). This is where most people over-shoot: a generally busy day is not "moderately active". Pick the level that matches a typical training week, and when in doubt choose one lower.
What the numbers look like
Take a 35-year-old woman, 70 kg at 165 cm. The five formulas put her resting burn between about 1,395 kcal (Mifflin–St Jeor) and 1,466 kcal (Harris–Benedict 1919). At a sedentary ×1.2 her TDEE is roughly 1,675–1,760 kcal; step up to moderate ×1.55 and it is about 2,160–2,270 kcal. The activity bracket shifts the number far more than the choice of formula does — which is why picking it honestly matters more than hunting for the “right” equation.
FAQ
What is TDEE?
TDEE — Total Daily Energy Expenditure — is roughly the calories your body uses in a day: your resting burn (BMR) plus everything you do on top, from walking to workouts. It is your maintenance line: eat around it and your weight holds. It is an estimate, so it is best read as a range.
How is TDEE calculated?
A formula estimates your resting burn (BMR) from sex, weight, height and age — or lean mass if you know your body fat — then multiplies it by an activity factor (about 1.2 sedentary to 1.9 very active). Because the formulas and the activity factor are each approximate, we run five formulas and show the spread as a range.
Is TDEE the same as maintenance calories?
Essentially, yes — your maintenance calories are your TDEE, the intake that keeps your weight steady. TDEE is the term for the estimate of your burn; "maintenance" is the same number seen from the goal side.
Which activity level should I choose?
Pick the one that matches a typical week, and if unsure, go one lower — over-estimating activity is the most common way a TDEE ends up too high. "Moderate" means real exercise 3–5 days a week, not a generally busy day. The honest test is two weeks of tracking against the number.
How accurate is a TDEE calculator?
BMR formulas are typically within about ±5–10% for most people, and the activity multiplier is a broad bracket, so any single TDEE figure can be off by a few hundred calories. That is why the number is a starting point — logging your intake and watching your weight trend refines it far more than any equation.