Menu

Search toolsChangelog

to move to openDescribe the problem, not the tool

Daily calories with a desk job

A sedentary day multiplies your resting rate by about 1.2. For the example on this page that is 1,644 calories rather than the 2,124 the same person needs training three to five times a week — a difference of 480 a day. The 2,000-calorie figure on a food label is a labelling reference for the whole population, not an estimate for any particular person: a 65 kg woman at a desk sits well below it and a 90 kg man well above.

The equation carries a different constant for each, reflecting the average difference in lean mass. It was published with two, so this is the only choice it offers.

The equation was derived on adults aged 19 to 78. Outside that band it is an extrapolation rather than a prediction.

Standing height, without shoes.

Total body weight, not lean mass. That is why the equation is least accurate at the extremes of body composition.

This is the largest source of error in the answer. If you are between two rungs, take the lower one.

Calories to maintain your weight
1,644
Your resting rate multiplied by the activity level. This is the figure people mean by TDEE.
Resting rate (BMR)
1,370
Everything above resting
274
Calories for your chosen pace
1,644

Your figure at each activity level

Sedentary1.21,644
Lightly active1.3751,884
Moderately active1.552,124
Very active1.7252,364
Extremely active1.92,603

An estimate, not medical advice. Body metrics are population averages and do not account for your individual circumstances. Speak to a clinician about anything that matters.

Daily calories at each activity level
Chart type for “Daily calories at each activity level”
0 500 1K 1.5K 2K 2.5K 3K Sedentary Very active
0 500 1K 1.5K 2K 2.5K 3K Sedentary Very active
0 500 1K 1.5K 2K 2.5K 3K Sedentary Very active
0 500 1K 1.5K 2K 2.5K 3K Sedentary Very active
0 500 1K 1.5K 2K 2.5K 3K Sedentary Very active
0 500 1K 1.5K 2K 2.5K 3K Sedentary Very active

The same body at every rung of the ladder. Sedentary to extremely active is about 960 calories a day apart.

What to take away
  1. A sedentary multiplier of 1.2 still covers standing, walking about the house and digesting food. It does not mean bed rest.

  2. Deliberate exercise moves the total less than people expect: three sessions a week takes the multiplier from 1.2 to about 1.375.

  3. At a desk, the resting rate is roughly five sixths of the whole day's energy use, so body size matters far more than the gym does.

How it works

The formula

Mifflin-St Jeor (1990), resting metabolic rate in kcal per day:

  men    BMR = 10 x weight + 6.25 x height - 5 x age + 5
  women  BMR = 10 x weight + 6.25 x height - 5 x age - 161

where
  weight = kilograms
  height = centimetres
  age    = years

Total daily energy expenditure:

  TDEE = BMR x activity multiplier

  1.200  sedentary
  1.375  lightly active
  1.550  moderately active
  1.725  very active
  1.900  extremely active

Calorie target for a chosen rate of weight change:

  target = TDEE + (kg per week x 7700 / 7)

  floored at 1200 kcal (women) and 1500 kcal (men)

What it assumes

  • The equation predicts a group average rather than you. Frankenfield's systematic review found it the most reliable of the equations tested, estimating resting rate to within 10% of a measured value more often than any other, while noting that errors and limitations remain.
  • The activity multiplier is a self-assessment and it is the largest source of error here. Each rung of the ladder is 0.175 of your resting rate away from the next, which is about 240 calories a day for the worked example below.
  • Body composition is ignored. The equation takes total body weight, so it tends to underestimate a muscular person and overestimate somebody carrying more fat at the same weight.
  • Weight change is converted at 7,700 kcal per kilogram. That holds for a few weeks and then overstates the loss, because maintenance falls as you get lighter.
  • The calorie target is never displayed below 1,200 kcal for women or 1,500 for men. Those are the top of the range the NHLBI's 1998 clinical guidance prescribes for a low-calorie diet, used here as a floor.
  • Nothing here accounts for pregnancy, breastfeeding, a thyroid condition, or medication that changes metabolic rate. It is not intended for anyone under 18.
  • Calorie means kilocalorie throughout, which is what a food label in Britain prints as kcal and an American one prints as Calories.

Common questions

Does a gym session move me out of sedentary?

Not on its own. The multipliers describe a whole week, and an hour of exercise three times a week is roughly the single step from sedentary to lightly active. What moves the number most is the eight hours either side of it — standing, walking and fidgeting outweigh the session.

Should I eat back the calories from a workout?

If the activity level you picked already includes your training, those calories are counted and eating them again double-counts. Fitness trackers overestimate exercise burn by a wide margin, so the safer approach is to set the activity level honestly and leave the daily figure alone.

Sources

The full method, worked example and every assumption behind this figure are on TDEE Calculator.