TDEE calculator
The gap between the lowest and highest multiplier is over half again as much energy: on the default figures, 1,937 kcal against 3,067, a spread of about 1,130 calories a day. Choosing the band is a bigger decision than any of the measurements, so the alternatives are listed rather than hidden behind one number.
A population estimate, not a measurement. Real expenditure varies by around 10% between people of identical size, and the activity multipliers are broad bands rather than precise factors.
Total daily energy expenditure is what you burn in twenty-four hours: your basal metabolic rate multiplied by an activity factor between 1.2 for a desk job and 1.9 for physical work or twice-daily training. Basal rate alone, meaning what the body uses at complete rest, is the largest part of the total for most people — on the bands here it runs from about 83 per cent at a desk job down to just over half at twice-daily training.
How to use this calculator
The multiplier is the part of this page that repays attention, because it carries more of the answer than the equation underneath it does. It is a physical activity level, or PAL, and a PAL is defined as total energy expenditure divided by basal rate — that definition, and the doubly-labelled-water work behind it, is FAO/WHO/UNU’s. The five multipliers here are not: 1.2, 1.375, 1.55, 1.725 and 1.9 are the conventional activity factors used alongside Mifflin–St Jeor and Harris–Benedict, and they are what almost every calculator of this kind applies. FAO tabulates something wider and coarser — three bands at 1.40–1.69, 1.70–1.99 and 2.00–2.40, with 1.40 to 2.40 given as the range a free-living adult can sustain. Two of the five here sit below that floor. Read the bands as lifestyles either way: 1.55 is not "three gym sessions a week", it is a whole way of living that happens to cost 55% above resting.
Expenditure has three parts, and only one of them is training. Basal rate is the largest and is what the equation estimates. Digestion takes roughly a tenth. Everything else is movement, most of which is not exercise at all: walking, standing, carrying, fidgeting, restlessness. James Levine's group at the Mayo Clinic overfed sixteen non-obese volunteers by 1,000 kcal a day for eight weeks and found that two thirds of the rise in daily expenditure came from this non-exercise activity, and that variation in it accounted for a tenfold difference in how much fat the volunteers actually stored. Two people with identical training can genuinely differ by several hundred calories a day, and none of it shows up in a workout log.
The practical consequence is that the band is a hypothesis, not a measurement. Pick the one that describes a normal week including the days nothing happens, then let a fortnight of scale readings correct it.
What people use it for
- Finding maintenance calories before deciding on a deficit or a surplus
- Seeing how much of the day’s total is resting rate and how much is movement
- Comparing what a desk week and a training week actually cost in calories
- Picking an activity band by looking at all five figures side by side
- Setting a starting number to adjust from after a fortnight on the scale
Questions
BMR is what you would burn lying still all day. TDEE is BMR plus digestion and everything you actually do. TDEE is the figure to eat against.
They are physical activity levels — total daily expenditure divided by basal rate — in the conventional five-band form used with Mifflin–St Jeor and Harris–Benedict. That ladder is a calculator convention rather than a published standard: FAO/WHO/UNU, which defines the PAL and measured it with doubly labelled water, publishes three wider bands running 1.40 to 2.40, so the lowest two steps here fall below the range it treats as sustainable for a free-living adult. They describe a way of living, not a number of workouts.
Whichever describes a normal week including the days you do nothing. Most people land one band lower than instinct suggests, because the sedentary hours outnumber the active ones by a wide margin.
The resting-rate half is good to about ten per cent for most people. The multiplier is far rougher, and it is applied to the largest number on the page, so the total inherits the wider error. Treat it as a starting point and adjust from the scale.
Less than commonly claimed. Skeletal muscle costs roughly 13 kcal per kilogram per day at rest, against about 4.5 for fat, so ten kilograms of extra muscle is worth well under a hundred calories a day. Organs, not muscle, do most of the resting burning.
This page tells you what you burn. The calorie calculator takes that figure and turns it into a target for a weight goal.