Calorie Burn Estimator
Compendium code 17200, 4.8 METs.
Energy cost
270 kcal
6 kcal a minute at this body weight.
- Above what resting would have cost214 kcal
- Using measured resting metabolism instead227 kcal
- Oxygen this asks for1,260 ml a minute
How this was worked out
- Activity and its MET valueWalking, 3.5 to 3.9 mph, level, brisk, firm surface, walking for exercise — 4.8 METs, Compendium code 17200
- Duration in hours45 min ÷ 60 = 0.75 h
- METs × kilograms × hours4.8 × 75 kg × 0.75 h × 1 kcal/kg/h = 270 kcal
- Less what resting would have cost270 kcal − (1 MET × 75 × 0.75) = 214 kcal
- The same sum on Byrne’s measured resting rate4.8 × 75 × 0.75 × 0.84 kcal/kg/h = 227 kcal
- Oxygen, at the Compendium definition4.8 × 3.5 ml/kg/min × 75 kg = 1,260 ml a minute
An estimate for training purposes and not medical advice. A MET value is an average measured across a group of people doing something a research team defined precisely, and your version of the same activity may be harder or easier than theirs by a wide margin. Nothing here knows your pace, your terrain, your technique or your body composition. The Compendium publishes no error bar on an individual reading, so this page does not invent one — but the part of the error that IS measured is large on its own: the conventional resting rate the whole scale is built on overstates energy expenditure by about 20%, which is the second figure shown above rather than a correction applied behind your back.
MET values are quoted, code and all, from the 2024 Adult Compendium of Physical Activities (Herrmann and colleagues, Journal of Sport and Health Science, 2024), which was built for adults aged 19 to 59 — data from people 60 and over was removed from this edition. One MET is defined as 3.5 ml of oxygen per kilogram per minute, or 1 kcal per kilogram per hour. Byrne and colleagues measured resting metabolism in 769 adults and found it averaged 0.84 kcal per kilogram per hour instead, meaning the conventional figure overstates energy expenditure by about 20%. Both readings are above rather than one chosen for you.
What a MET value actually is
A metabolic equivalent expresses the cost of an activity as a multiple of sitting still. One MET is defined as 3.5 millilitres of oxygen per kilogram of body weight per minute, which conveniently also works out at one kilocalorie per kilogram per hour — and that convenience is the entire calculation here. Multiply the MET value by your mass in kilograms and by the hours you spent doing it, and you have the energy cost.
A worked example: 45 minutes of brisk walking
Walking at 3.5 to 3.9 mph on a firm level surface is activity code 17200 in the Compendium and carries 4.8 METs. Forty-five minutes of it at 75 kg comes to 270 kilocalories, or six a minute. The same three quarters of an hour spent running ten-minute miles, code 12050 at 9.3 METs, comes to 523. Every one of those figures traces to a table row you can look up rather than to a coefficient invented for a calculator.
Gross, net, and a twenty per cent argument
The headline figure is gross: it includes the calories you would have spent anyway simply by existing for that time. Subtract one MET and you get the net cost, and that is the number that belongs in a calorie deficit. At 75 kg for 45 minutes the resting share is 56 kilocalories, so the walk above is 214 net rather than 270.
There is a deeper objection. Byrne and colleagues measured resting metabolism in 769 adults in 2005 and found it averaged 0.84 kilocalories per kilogram per hour, not the conventional one, meaning the whole MET system overstates energy expenditure by roughly a fifth. The tool shows that lower reading beside the standard one instead of quietly picking a side.
Who these numbers describe
Values come from the 2024 Adult Compendium of Physical Activities, published by Herrmann and colleagues in the Journal of Sport and Health Science. That edition was rebuilt specifically for adults aged 19 to 59, with data from people 60 and over removed from it, so it is not the right table for an older body. Each value is a group average from a laboratory, and individual costs for the same task vary widely with skill, terrain and efficiency of movement.
Why the treadmill says something else
Why does my treadmill report a larger figure?
Usually because it reports gross rather than net calories and assumes a body weight you may not have typed in, and sometimes because its internal table is older or unattributed. Machines that never asked your weight are working from a default, and body mass is the largest single term in the whole calculation.
Should I eat these calories back?
Cautiously if at all. Between the gross-versus-net distinction and the twenty per cent overstatement in the MET convention itself, an honest error band on an hour of exercise is easily a hundred kilocalories wide. Eating back a conservative fraction, and adjusting against what the scale does over several weeks, survives that uncertainty better than trusting the number.
My activity is not in the list.
The Compendium contains over a thousand activities across 22 headings and this page offers a readable subset of them. The full tables are published openly, so the reliable move is to look up the closest published description and use its value, rather than picking something roughly similar from here and hoping the intensity matches.
Does being muscular or heavy change the estimate?
Body mass is already in the formula, so a heavier person doing the same activity gets a proportionally larger figure. What the model cannot see is composition: two people of identical weight with very different amounts of muscle have different resting metabolisms, and the MET convention assumes one value for both of them.