TDEE Calculator — total daily energy expenditure (FAO/WHO/UNU PAL)

How it works

TDEE answers "how much energy do I actually use", where BMR answers only "how much do I use at rest". The link between them is the physical activity level, defined by the FAO/WHO/UNU expert consultation as total energy expenditure divided by basal metabolic rate — so multiplying back the other way, energy requirement = PAL × BMR. BMR here uses the Mifflin-St Jeor equation, the same one the BMR page reports.

A note on our activity numbers. Almost every TDEE calculator multiplies BMR by 1.2, 1.375, 1.55, 1.725 or 1.9, usually captioned "Harris-Benedict activity factors". Those five numbers appear in neither Harris and Benedict's 1919 paper nor Roza and Shizgal's 1984 revision, and we could not find any publication that issues them — so we don't use them. The lowest of them, 1.2, is also below the 1.40 floor the FAO/WHO/UNU consultation gives for free-living adults. This page uses that consultation's three published lifestyle categories instead, which is also what the NIH Body Weight Planner does. Expect our numbers to differ from other calculators; ours are the ones with a source behind them.

Worked example

The consultation's own example: a man with a PAL of 1.75 and a BMR of 7.10 MJ/day (1,697 kcal/day) needs 1.75 × 7.10 = 12.42 MJ/day, or 2,970 kcal/day.

The category values come from worked 24-hour activity budgets in the report. For the sedentary example — eight hours sleeping, eight sitting at work, plus personal care, eating, cooking, housework, driving and light leisure — the energy costs sum to 36.7 times the hourly BMR, and 36.7 ÷ 24 = 1.53. The active budget sums to 42.2, giving 1.76, and the vigorous one to 53.9, giving 2.25. Each sits inside its published band.

The consultation also works each category through to a real population, which is the clearest check that these factors do what we use them for. A sedentary group of women aged 30–50 averaging 55 kg, with a BMR of 5.40 MJ/day (1,290 kcal), has a total expenditure of 1.53 × 5.40 = 8.26 MJ/day (1,975 kcal). A moderately active group of women aged 20–25 at 5.60 MJ/day works out to 1.76 × 5.60 = 9.86 MJ (2,355 kcal), and a vigorously active male group at 7.30 MJ/day to 2.25 × 7.30 = 16.42 MJ (3,925 kcal).

Frequently asked questions

What's the difference between BMR and TDEE?

BMR is the energy your body uses at complete rest — breathing, circulation, brain and organ function — measured lying down, fasted and relaxed. TDEE adds everything else: moving, working, exercising, and the energy cost of digesting food. BMR is typically 45–70% of TDEE in adults, so activity accounts for a large share of what you actually burn.

Which lifestyle category should I pick?

Sedentary or light covers occupations without much physical effort, little walking, motorised transport, and no regular exercise. Active or moderately active describes work that keeps you moving or a lighter job combined with regular exercise. Vigorous covers physically demanding work — agricultural labour without machinery, for example. Pick by your whole 24 hours, not just your job: the consultation deliberately based the categories on occupational *and* discretionary activity together, because people with light jobs can be very active outside them and vice versa.

Why don't your numbers match other TDEE calculators?

Because the multipliers differ. Most sites use five values whose source we could not establish; we use the three FAO/WHO/UNU publishes. If another calculator gives you a lower sedentary figure, it is likely applying 1.2 — a value below the range the consultation says free-living adults occupy.

How accurate is this?

It is an estimate built from two estimates. The BMR equation predicts a population average and can be off by 10% or more for an individual; the PAL category is a band, not your measured value, and real people fall anywhere inside it. Treat the result as a starting point to adjust from, not a measurement — the only accurate way to know your expenditure is doubly labelled water or indirect calorimetry.

Can my PAL be higher than 2.40?

Briefly, yes — endurance athletes in training and people doing sustained heavy labour can exceed it. The consultation caps the published range at 2.40 because values above that are difficult to maintain over a long period, so it isn't a useful planning figure for most people. The NIH Body Weight Planner allows up to about 2.5 for the same reason.

Does this account for the calories burned digesting food?

Yes, implicitly. PAL is derived from measured total energy expenditure divided by BMR, and total expenditure includes the thermic effect of food. It isn't broken out as a separate line because the measurement it comes from doesn't separate it either.

What does this exclude?

Growth, pregnancy and lactation all add energy needs the adult categories don't cover, and the equations are not validated for children or adolescents. It also excludes illness, injury recovery, extreme environments, and any medical condition affecting metabolism. It gives you an energy figure only — how to distribute it across foods is the macro page's job.