MathBench

Calories Burned Calculator

Estimate the energy cost of an activity from its MET value and your body weight — with the gross and net figures shown separately, and an option to correct the resting rate that the standard formula simply assumes.

Estimates, not medical advice. These calculators apply published equations to the numbers you enter. They describe averages across large groups, and any individual can differ from the average by a wide margin — metabolism, body composition, medication, and medical conditions all shift the result. Nothing here diagnoses, treats, or replaces advice from a doctor or registered dietitian, and no target produced by a formula should override how you actually feel. If you are managing a health condition, are pregnant, or have a history of disordered eating, talk to a clinician before acting on any of it.

Energy cost

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Gross against net

The same session at other durations

A general-wellness estimate, not a diagnosis. It cannot tell you whether you are healthy — only where a measurement falls on a published scale. Everything is calculated in your browser: nothing you type is sent anywhere or stored. If counting is making things worse rather than better, the National Eating Disorders Association keeps a current list of support options.

How this calculator works

The calculation is short and the reasoning behind it is worth following, because the same three numbers underpin every calorie estimate a treadmill or a watch will ever show you. A MET is a multiple of resting energy use, and the convention fixes resting oxygen uptake at 3.5 millilitres per kilogram per minute. Multiply the MET value by that rate and by your body weight and you have oxygen consumed per minute; a litre of oxygen releases roughly 5 calories, so dividing by a thousand and multiplying by five turns oxygen into energy. Those two steps collapse into the familiar division by 200.

The page reports two figures rather than one. Gross energy use is the total during the session. Net subtracts the resting cost you would have paid regardless — you were always going to burn something during that hour. The distinction barely matters for hard running, where rest is a tenth of the total, and matters enormously for gentle activity, where it can be nearly half. If you are eating back exercise calories against a daily target, the net figure is the one that avoids counting the same energy twice.

There is a deeper problem the page also handles. That 3.5 figure is a convention rather than a measurement, and studies that actually measure resting oxygen uptake find it too high for nearly everyone — by roughly a third on average, and by more for people with higher body fat or lower fitness. The personalised option predicts your own resting rate from height, weight, age and sex, and uses it in the two places it genuinely belongs: as the resting cost subtracted from the gross figure, and as the baseline for saying how intense the activity is for you. It deliberately does not rescale the calories themselves, because the oxygen an activity consumes is a property of the activity rather than of the person's metabolism at rest.

The formula

Gross energy use:
    kcal/min = METs × 3.5 × body mass (kg) ÷ 200
    kcal     = kcal/min × minutes

Where the 200 comes from:
    METs × 3.5           →  mL O₂ per kg per minute
    × body mass (kg)     →  mL O₂ per minute
    ÷ 1000               →  L O₂ per minute
    × 5 kcal per L O₂    →  kcal per minute
    and 5 ÷ 1000 = 1 ÷ 200

Net (activity only):
    kcal_net = (METs − 1) × 3.5 × kg ÷ 200 × minutes

Personalised correction:
    your resting rate (mL/kg/min) = RMR kcal/day ÷ 1440 ÷ 5 × 1000 ÷ kg
    corrected MET = published MET × 3.5 ÷ your resting rate

MET values come from the Compendium of Physical Activities, compiled by Barbara Ainsworth and colleagues and published in its 2011 revision in Medicine & Science in Sports & Exercise 43 (2011) 1575–1581. It is the reference behind essentially every calorie-burn figure in consumer fitness technology. A 2024 edition has since been published, with some values revised in each direction, so an activity that matters precisely is worth checking against the current entry.

The critique of the 3.5 convention comes from measurement studies: N. M. Byrne and colleagues, "Metabolic equivalent: one size does not fit all," Journal of Applied Physiology 99 (2005) 1112–1119, measured resting oxygen uptake in 769 adults and found a mean of about 2.6 millilitres per kilogram per minute, with only around 2 percent of participants reaching the assumed 3.5. Later work by Kozey and colleagues found the resulting intensity misclassification fell hardest on people who were less fit or heavier — meaning the standard formula is least accurate for the people most likely to be using it. The personalised correction here rescales the published MET by the ratio of the assumed resting rate to a predicted individual one, which is the adjustment those authors propose.

Worked example

An 80 kg person running a ten-minute mile for 45 minutes — the calculator's default. Running at 6 mph carries a Compendium value of 9.8 METs:

  1. Oxygen per kilogram: 9.8 × 3.5 = 34.3 mL/kg/min
  2. For an 80 kg body: 34.3 × 80 = 2,744 mL/min, which is 2.744 litres per minute
  3. Energy: 2.744 × 5 kcal per litre = 13.72 kcal/min (the same as 9.8 × 3.5 × 80 ÷ 200)
  4. Gross for 45 minutes: 13.72 × 45 = 617 kcal
  5. Resting cost over the same 45 minutes: 1 × 3.5 × 80 ÷ 200 = 1.4 kcal/min, so 63 kcal
  6. Net, the part the run actually added: 617 − 63 = 554 kcal

Now switch the resting rate to personalised. For a 30-year-old man of 180 cm, predicted resting metabolism is 1,780 calories a day, which is 1.24 calories a minute — or about 3.09 millilitres of oxygen per kilogram per minute, below the assumed 3.5. The gross figure is unchanged, because the run costs what it costs. The resting deduction falls from 63 to 56 calories, so the net figure rises slightly to about 562. The more interesting output is the other one: measured against his own resting rate, that run is 11.1 METs rather than 9.8 — meaningfully harder relative to him than the label implies.

Assumptions & tips

  • Use net calories against a food target. Your daily calorie target already includes resting metabolism for all 24 hours. Adding the gross figure for a workout counts that hour's resting burn twice, which is a small error for a hard run and a large one for a long walk.
  • Count moving time, not elapsed time. An hour at the gym is rarely an hour of work. Rest between sets, queueing for equipment and stretching are all near-resting, and including them inflates the estimate more than any choice of MET value.
  • Expect your watch to read high. Consumer trackers use the same MET convention with the same optimistic resting assumption, often on top of heart-rate models that struggle during strength work. Treat their numbers, and these, as rough.
  • Do not treat exercise as a licence to eat back. The error bars here are wide enough that eating back a precise number is false precision. If you are managing weight, adjust intake based on what your weight trend actually does over weeks.
  • Intensity matters more than the label. "Cycling" spans 4 to 16 METs depending on effort. Pick the entry that matches how hard you were actually working, not the activity's name, and prefer the lower option when in doubt.
  • The activity is not the whole story. Regular movement improves cardiovascular health, insulin sensitivity, mood and sleep whether or not it burns an impressive number. Energy expenditure is the least interesting benefit of exercise, and the one most likely to disappoint if you focus on it.

Frequently asked questions

What is a MET?

A metabolic equivalent of task — a multiple of resting energy use. An activity rated at 8 METs is defined as costing eight times the energy of sitting quietly. The convention fixes that resting rate at 3.5 millilitres of oxygen per kilogram of body weight per minute, which makes the arithmetic simple: multiply METs by body weight and duration, and you have calories. The Compendium of Physical Activities catalogues MET values for hundreds of activities, and it is the source virtually every calorie-burn calculator and fitness tracker draws on, whether or not they say so.

Why does the calculator show two different numbers?

Because "calories burned by exercise" is ambiguous, and the difference is not small. The gross figure is your total energy use during the activity. The net figure subtracts what you would have burned anyway just by existing for that time — the resting cost you cannot avoid. For a hard run the distinction is minor, around 10 percent. For an hour of yoga at 2.5 METs, 40 percent of the gross figure is simply the cost of being alive. If you are adding exercise calories to a daily food target, the net figure is the honest one to use, since your daily target already accounts for resting metabolism.

Does this overestimate how much I burn?

For most people, yes, and the reason is built into the definition. The 3.5 millilitres per kilogram per minute that defines one MET is a convention, not a measurement, and studies measuring actual resting oxygen uptake find it too high for almost everyone — one study of 769 adults found only about 2 percent actually reached it, with the convention overestimating resting metabolism by roughly 35 percent on average. Because MET values scale from that resting figure, the error carries through. Worse, it is not evenly distributed: the overestimate is largest for people with higher body fat, lower fitness, and greater age. The personalised option addresses the part of this that a calculator legitimately can — it subtracts your own predicted resting rate rather than the convention, and tells you what the activity costs relative to your rest. It deliberately does not rescale the gross calorie figure, because the oxygen an activity consumes belongs to the activity rather than to the person doing it.

How does the personalised option work?

It replaces the assumed resting rate with one predicted from your own body, and it is careful about where that correction belongs. The energy an activity costs is a property of the activity — running a ten-minute mile consumes about the same oxygen per kilogram whoever does it — so the gross figure does not change. What does change is the resting cost subtracted to get the net figure, which should be your actual resting metabolism rather than a convention. The option also reports how many of your own METs the activity represents, which is usually more than the published label: if your resting rate is below 3.5, every activity is harder relative to you than the Compendium number suggests.

Which edition of the Compendium is this?

The 2011 Compendium, which remains the most widely cited and the basis of most published research. An updated edition was released in 2024, and some values moved in both directions — several walking intensities rose while some running values fell. Where an activity matters to you precisely, check the current Compendium entry rather than relying on any calculator, including this one. The values here are population averages in any case, and individual energy cost for the same activity varies substantially with technique, terrain, and fitness.

Sources

  1. 2011 Compendium of Physical Activities: a second update of codes and MET values — B. E. Ainsworth, W. L. Haskell, S. D. Herrmann and colleagues, Medicine & Science in Sports & Exercise 43(8), 1575–1581, 2011. doi.orgThe MET value attached to every activity in this calculator's list, and the 3.5 mL of oxygen per kg per minute convention that one MET is defined against.
  2. Compendium of Physical Activities — the Compendium research team, led by Barbara E. Ainsworth. pacompendium.comThe authors' own searchable database, where an activity whose value matters precisely can be checked against the current entry rather than this page's fixed list.
  3. 2024 Adult Compendium of Physical Activities: A third update of the energy costs of human activities — S. D. Herrmann, E. A. Willis, B. E. Ainsworth and colleagues, Journal of Sport and Health Science 13(1), 6–12, 2024. pmc.ncbi.nlm.nih.govThe newer edition this page's FAQ points readers to, and the reason it says values have moved in both directions since 2011.
  4. Metabolic equivalent: one size does not fit all — N. M. Byrne, A. P. Hills, G. R. Hunter, R. L. Weinsier and colleagues, Journal of Applied Physiology 99(3), 1112–1119, 2005. doi:10.1152/japplphysiol.00023.2004 — cited without a link because the publisher's site did not serve a verifiable response at the time of writing. The measurement study behind this page's warning that the 3.5 convention runs high, and behind the personalised option that substitutes a predicted individual resting rate.
  5. Errors in MET Estimates of Physical Activities Using 3.5 ml·kg−1·min−1 as the Baseline Oxygen Consumption — S. Kozey, K. Lyden, J. Staudenmayer and P. Freedson, Journal of Physical Activity and Health 7(4), 508–516, 2010. doi:10.1123/jpah.7.4.508 — cited without a link because the publisher's site did not serve a verifiable response at the time of writing. The finding that intensity misclassification from the standard baseline falls hardest on people who are heavier or less fit, which is why this page offers the correction at all.
  6. A new predictive equation for resting energy expenditure in healthy individuals — M. D. Mifflin, S. T. St Jeor and colleagues, American Journal of Clinical Nutrition 51(2), 241–247, 1990. doi.orgThe equation the personalised option uses to predict your own resting metabolic rate, which replaces the assumed 3.5 baseline in the resting deduction and in the "your METs" figure.

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    Daily calorie needs from the Mifflin-St Jeor equation — resting rate, maintenance, a goal target, and a macro split, with the uncertainty stated.

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