TDEE Explained: The Number Behind Every Diet Plan
Total daily energy expenditure is everything you burn in a day. It is the number every plan is built on, and it is calculated by taking your resting rate and multiplying by an activity factor. The TDEE Calculator does it from your training days.
The four parts
BMR, what you burn at rest, is the bulk of it - the BMR Calculator covers that alone.
The thermic effect of food is the energy spent digesting, around ten per cent of what you eat. Protein costs more to process than carbohydrate or fat, which is a real effect and a small one.
Deliberate exercise is the part everyone thinks about and is often the smallest.
Everything else you do while awake - walking, standing, fidgeting, carrying things - is the part nobody counts and it varies enormously between people. The gap between a desk job with a car and a job on your feet can be several hundred calories a day without either person exercising.
The multiplier is the weak link
Activity multipliers run from about 1.2 for sedentary to 1.9 for very heavy training. The problem is that almost everybody picks one too high.
"Moderately active, exercise three to five days a week" sounds like an honest description of someone who goes to the gym three times. But the multiplier is meant to cover the whole week including the rest of the day, and three hours of gym across a week spent otherwise sitting is closer to lightly active. Overshooting by one category is 200 to 400 calories, which is large enough to explain most plans that quietly do not work.
Choose one category lower than feels right. If the resulting weight trend says you were too conservative, that is easy to correct upward.
Finding your real number
The calculation gives you a starting point; two or three weeks of data gives you the truth. Eat at the estimate, weigh yourself consistently, and watch the trend rather than the daily figure. Stable weight means the estimate matched your actual expenditure, which is more information than any equation can give you.
It also moves. A week of illness, a holiday, a new job on your feet, a cold spell - all shift it, which is why a single number pinned down once is not a thing anyone really has.
Common questions
Why is my TDEE lower than my friend's at the same weight?
Lean mass, age, genetics and all the unmeasured daily movement. Two people of identical weight can differ by several hundred calories.
Does a fitness tracker measure it?
It estimates it, and the estimates for calorie burn are among the least accurate things trackers do - errors of twenty to thirty per cent are common. Step counts are far more reliable than the calorie figures derived from them.
Should I eat back my exercise calories?
If your multiplier already accounted for that training, adding it again double-counts it. Pick one approach.
How do I split the total into protein, carbs and fat?
That is the next step, and the Macro Calculator does it.
Want a starting estimate for yours?