The formula
How to calculate tDEE
Total daily energy expenditure is everything your body burns in a day: resting metabolism plus movement, exercise and the energy used digesting food. It is the number that decides whether you gain, lose or hold weight.
The activity multiplier is the weak link and people routinely overestimate it. Desk work with two or three gym sessions a week is 1.375 to 1.55, not 1.725 — that level implies physical work or daily hard training.
The inputs, one by one:
- Weight (kg)
- Height (cm)
- Age (years)
- Activity multiplier (×) — 1.2 sedentary, 1.375 light, 1.55 moderate, 1.725 hard, 1.9 very hard
No submit button: type and the answer moves. Your inputs end up in the link, so the page can be shared already filled in.
Consistency in how the underlying measurements are taken matters more than precision to the last decimal — measuring at the same time of day, in the same state of rest or hydration, makes readings taken weeks apart genuinely comparable in a way that a single very precise reading on its own is not.
Why tDEE matters
This kind of calculation gets used both out of general interest and ahead of a specific conversation — with a trainer, a midwife or a GP — where having an actual number ready, rather than a description, makes that conversation more concrete and specific.
It is most useful tracked over time rather than read once — a single reading tells you where you are today, while the same calculation repeated weeks or months apart, using the same method each time, shows the direction things are actually moving in.
None of the figures produced on this page are intended to replace a proper assessment, and nothing here should be read as a diagnosis or a treatment recommendation. What a calculator like this is good for is preparation — arriving at an appointment with an actual number already in hand, rather than a vague sense of a change, tends to make that conversation more useful for everyone involved.
In practice, this kind of figure is often calculated more than once with slightly different inputs to see how sensitive it is — trying a measurement taken this morning against one taken yesterday evening, for instance, to see how much normal daily variation actually moves the result. That habit is a good one: it builds a feel for how much a single reading can be trusted on its own before drawing any conclusion from it.
Worked example
Take the figures the calculator starts with:
- Weight: 75 kg
- Height: 175 cm
- Age: 35 years
- Activity multiplier: 1.55 ×
That gives:
- TDEE, male equation: 2,594 kcal/day
- TDEE, female equation: 2,337 kcal/day
- For 0.5 kg a week loss, male equation: 2,044 kcal/day
Those starting figures exist only to show the calculation working, not as a target or a reference value to compare yourself against — replace them with your own measurements in the calculator above and the same formula applies exactly as shown.
Reading the result
Treat the result as a starting hypothesis. Track intake and weight for two or three weeks; if weight holds steady, your true TDEE is whatever you were eating, and that measured figure beats any equation.
Where this goes wrong. Very low intakes backfire. Deficits beyond about 25% of TDEE cost muscle as well as fat and are hard to sustain. This is general information, not medical or dietary advice — speak to a professional before making significant changes.
As with any general-purpose formula, the result here is an estimate derived from population averages, not a measurement specific to you — a reasonable starting point for a conversation with a qualified professional, not a replacement for one. Nothing on this page is medical advice.
The BMR part is usually within 10%. The activity multiplier is much rougher, so the overall figure can be out by 300 kcal or more in either direction. It is a starting point to adjust from, not a measurement.
Yes, and it falls. A smaller body needs less energy to move and maintain, so a deficit that worked at the start stops working later. Recalculate every 5 kg or so.
The headline figure is tDEE, male equation. With 75 kg weight, 175 cm height and 35 years age, that comes to 2,594 kcal/day. Change any field and the figure moves with it.
It uses a published formula applied exactly as defined, so the arithmetic itself is precise — but the formula is a population-level estimate, and individual results can vary from it for reasons the formula has no way to account for. Treat the output as a reasonable estimate rather than a measured or diagnostic value.
For most people, yes — a single reading is a snapshot, while the same measurement repeated consistently over weeks or months shows a trend, which is generally more informative than any one figure taken in isolation.
Small differences between calculators usually come down to which published formula or reference dataset each one uses — several equations in this area exist in more than one accepted version. This page states the specific formula used in the section above, so it is possible to check directly whether another source is using the same one.