TDEE Calculator
TDEE is total daily energy expenditure — everything you burn in a day, from staying alive to moving around. It is the number a calorie target is set relative to, and this calculator derives it from the Mifflin-St Jeor equation, the best-validated of the predictive formulas for a general adult population.
Your result
Fill in the fields on the left and your result appears here.
How TDEE is calculated
The calculation happens in two steps. First, a predictive equation estimates your resting metabolic rate — what you burn doing nothing at all, which for most people is the large majority of daily expenditure. Then that figure is multiplied by an activity factor to account for everything else.
Mifflin-St Jeor uses weight, height, age and sex. It has consistently outperformed older equations against measured expenditure in general adult populations, which is why it is the default here.
- Resting metabolic rate typically accounts for around 60–70% of total expenditure for a moderately active person.
- The activity multiplier ranges from 1.2 for sedentary to 1.9 for extremely active, and covers both deliberate exercise and everything else you do.
- The thermic effect of food — energy spent digesting — is folded into the multiplier rather than calculated separately.
- Everyday non-exercise movement varies enormously between people and is the single largest source of error in any estimate.
Track it, don't recalculate it.
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Treat it as a starting point
A predictive equation estimates a population average. Individual metabolic rates scatter around that average by a meaningful margin, driven by body composition, genetics, thyroid function and how much you move without thinking about it.
The useful approach is to take the number as an opening hypothesis, eat at it consistently for two or three weeks, and adjust based on what actually happens to your weight. That empirical correction is worth more than any refinement of the formula, because it accounts for your actual metabolism rather than a modelled one.
It is also worth knowing that expenditure falls as you lose weight — a smaller body costs less to run, and the reduction is somewhat larger than the size change alone predicts. A target that worked at the start of a phase will not still be right several months in.
Frequently asked questions
This calculator is general information for healthy adults, not medical or dietary advice. It applies published population formulas and cannot account for your clinical situation. Where a clinician has set you a target, that target replaces this one.
Built by the Pep AI team.