The MET Value Reference provides personalised calorie estimates for over 120 activities from the Ainsworth 2011 Compendium of Physical Activities, the standard reference used in exercise science research.
What One MET Actually Means
A MET is a standardised unit that expresses the energy cost of an activity as a multiple of resting metabolism. One MET is defined as the rate of energy expenditure while sitting quietly — approximately 3.5 millilitres of oxygen consumed per kilogram of body weight per minute, or roughly 1 kilocalorie per kilogram per hour. When an activity is rated at 7.0 METs, it means that activity costs seven times more energy than sitting still.
This ratio-based system is what makes MET values so practical. Because the energy cost is expressed relative to rest and scaled by body weight, a single MET number can apply across different body sizes. A 60 kg person and a 90 kg person performing the same 7.0-MET activity will burn different absolute calorie amounts, but the MET value itself remains constant. The individual scaling happens when you multiply MET by body weight. For a detailed look at how your resting metabolic rate forms the 1-MET baseline, the BMR calculator breaks down the underlying physiology.
MET Intensity Zones: Light, Moderate, and Vigorous
Exercise science classifies physical activity into three intensity zones based on MET values. These categories align with public health guidelines from organisations including the World Health Organization and the American College of Sports Medicine.
Light-intensity activities fall below 3.0 METs and include standing, slow walking, light stretching, and most desk-based work. Moderate-intensity activities range from 3.0 to 6.0 METs and encompass brisk walking, recreational cycling, gardening, and water aerobics. Vigorous-intensity activities exceed 6.0 METs and include running, competitive sports, heavy resistance training, and high-intensity interval sessions.
The WHO recommends 150-300 minutes per week of moderate-intensity activity or 75-150 minutes of vigorous-intensity activity for adults. Using MET values, you can verify whether your chosen activities actually qualify as moderate or vigorous rather than relying on subjective perception alone. Many people overestimate their exercise intensity — a casual bike ride at MET 4.0 is moderate, not vigorous, despite feeling effortful to a sedentary individual. The interactive calorie burn calculator applies these MET values to your specific body weight and session duration for personalised estimates.
Converting MET Values to Calories
The conversion from MET to calories is one of the simplest and most useful formulas in exercise science:
Calories per hour = MET value × body weight in kg
For shorter durations, divide the hourly figure proportionally. A 75 kg person performing a 7.0-MET activity burns approximately 525 kcal per hour, 263 kcal per 30 minutes, or about 9 kcal per minute. This formula works because the MET definition already incorporates the ~1 kcal/kg/hour resting energy cost, so the multiplication directly produces kilocalories.
One nuance worth noting: the calorie figure produced by this formula includes resting energy expenditure. If you want to know how many additional calories the activity burns above what you would have spent sitting, subtract your resting rate (1 MET × body weight) from the total. For the 75 kg person jogging at MET 7.0, the total is 525 kcal/hr but the excess above resting is 525 - 75 = 450 kcal/hr. This "above resting" figure is more relevant for exercise planning and total daily energy expenditure calculations where resting metabolism is already counted separately.
Limitations of MET-Based Estimates
MET values are population averages derived from laboratory measurements across groups of participants. Several factors cause individual energy expenditure to deviate from these averages.
Fitness level has a notable effect: trained individuals performing a familiar activity often exhibit lower oxygen consumption (and therefore lower actual METs) than the Compendium value suggests, because neuromuscular efficiency improves with practice. A competitive rower expends less energy per stroke than a recreational rower at the same pace. Body composition also matters — two people weighing 80 kg will have different metabolic responses if one carries 15% body fat and the other carries 30%, because muscle tissue is more metabolically active during movement. Environmental conditions (heat, cold, altitude, humidity), caffeine intake, and even the specific technique used within an activity all introduce further variation.
For these reasons, MET-based calorie estimates should be treated as useful approximations for planning and comparison rather than precise measurements of individual energy expenditure. The Compendium authors themselves note that MET values are best used for ranking activities by relative intensity and for epidemiological research, not for precise individual prescriptions. You can pair MET data with walking-specific calorie and distance estimates for the most common daily activity, or convert steps to distance for walking activities to quantify the volume of your daily movement.
A Brief History of the Compendium
The Compendium of Physical Activities was first published in 1993 by Barbara Ainsworth and colleagues as a standardised coding system for physical activity research. Before the Compendium, researchers used inconsistent activity descriptions and MET assignments, making it difficult to compare results across studies. The original version catalogued MET values for several hundred activities drawn from published indirect calorimetry data.
Updates followed in 2000 and 2011, each expanding the activity list, refining MET assignments based on new laboratory data, and improving the coding taxonomy. The 2011 edition — the version used by this reference tool — includes over 800 specific activities organised into 21 major categories. It remains the most widely cited resource for activity energy costs in exercise science, public health surveillance, and clinical research. The Compendium is maintained as an open resource, and its MET values inform the calculations behind tools like the running pace calculator and activity-specific energy estimates throughout exercise physiology research. For individuals working on body recomposition goals, understanding the energy cost of different activities helps balance training volume with nutritional targets.
Key Terms
Metabolic Equivalent (MET)
A physiological unit expressing the energy cost of physical activity as a ratio to resting metabolism. One MET equals approximately 3.5 mL O₂/kg/min or ~1 kcal/kg/hour. The Ainsworth 2011 Compendium assigns MET values to over 800 activities based on indirect calorimetry measurements. Values range from 0.9 (sleeping) to over 18 (sprinting), with most common exercises falling between 3.0 and 12.0 METs.
Resting Metabolic Rate (RMR)
The rate of energy expenditure at complete physical rest in a thermoneutral environment, measured after an overnight fast. RMR is closely related to — but not identical to — basal metabolic rate (BMR), which requires stricter measurement conditions. For practical purposes, 1 MET approximates RMR, and the difference between RMR and BMR is typically less than 10%. RMR accounts for 60-75% of total daily energy expenditure in most adults and is the physiological baseline against which all MET values are scaled.