METs and Calories Burned, Explained

By Udit Agarwal · Updated October 17, 2026

A MET, short for metabolic equivalent of task, compares the energy an activity uses with the energy you use sitting quietly: 1 MET is rest, and an activity rated 8 METs takes about eight times as much. To estimate the calories an activity burns, multiply its MET value by 3.5 and by your weight in kilograms, divide by 200, then multiply by the number of minutes. Running at 6 mph is rated 9.8 METs in the table the ArrayKit calculator uses, so a 70 kg runner burns about 360 calories in 30 minutes.

What is a MET?

The Compendium of Physical Activities, the standard catalogue of MET values, defines a MET as the ratio of the energy you use during an activity to the energy you use at rest. By convention, 1 MET is an oxygen uptake of 3.5 millilitres per kilogram of body weight per minute, the oxygen cost of sitting quietly. The same unit is often given as about 1 kilocalorie per kilogram per hour.

Because a MET is already scaled to body weight, it describes the activity rather than the person. Brisk walking at 4 mph is 5 METs whether you weigh 50 kg or 100 kg. The heavier walker burns twice as many calories doing it, but the rating does not change.

Health guidelines use METs to sort activities by intensity. The World Health Organization (WHO) and the US Physical Activity Guidelines both class 3 to under 6 METs as moderate and 6 or more as vigorous, and the US guidelines call anything lighter than 3 METs, other than sitting or lying down, light activity. With the values from the ArrayKit table:

The calories burned formula

The ArrayKit calculator uses the standard MET equation:

Calories = MET × 3.5 × weight (kg) ÷ 200 × minutes

Each piece has a job. MET × 3.5 is the oxygen used per kilogram of body weight per minute, in millilitres. Multiplying by your weight gives the millilitres of oxygen your whole body uses each minute. The body releases roughly 5 kilocalories of energy for every litre of oxygen it uses, so dividing by 1,000 (millilitres to litres) and multiplying by 5 turns oxygen into calories, and 5 ÷ 1,000 is the 1 ÷ 200 in the formula. The 5 is rounded: the real figure runs from about 4.7 when the body is burning mostly fat to just over 5 when it is burning only carbohydrate.

Over an hour the formula comes to 1.05 × MET × weight, so it gives 5 percent more than the "1 kilocalorie per kilogram per hour" shortcut. For the 70 kg runner, the shortcut gives 9.8 × 70 × 0.5 = 343 calories in half an hour, against 360 from the full formula.

Worked examples

Each row uses the formula and the MET value from the ArrayKit table.

The formula also works backwards. At 70 kg, brisk walking burns 5.0 × 3.5 × 70 ÷ 200 = 6.125 calories a minute, so burning 300 calories takes about 49 minutes.

For running, speed changes the rate far more than the total for a set distance. With the table's values, a 70 kg runner uses about 122 calories per mile at 5 mph (12 minutes a mile), 120 at 6 mph (10 minutes) and 108 at 8 mph (7.5 minutes). Faster running burns more each minute but is over sooner, and all three work out to roughly 1 calorie per kilogram of body weight per kilometre. The Pace Calculator converts between pace and speed if your watch shows minutes per mile or per kilometre.

Gross and net calories

The formula gives gross calories: everything you burn during the session, including the 1 MET you would have used anyway at rest. For the 30-minute run, that resting share is 1 × 3.5 × 70 ÷ 200 × 30, about 37 calories, so the extra energy the run itself cost is about 323. To get this net figure, use MET − 1 in place of MET.

The gap matters most for gentle activities. For slow walking at 2.8 METs, more than a third of the gross figure is energy you would have used sitting down. It also explains a common double count. A daily calorie estimate built with an activity multiplier, like the ones in Daily Calorie Needs, Explained and the TDEE Calculator, already includes your usual exercise, so adding workout calories on top counts them twice.

The Compendium of Physical Activities

The standard source of MET values is the Compendium of Physical Activities, first published in 1993 by Barbara Ainsworth and colleagues and updated in 2000, 2011 and 2024. It gives each activity a code and a MET value taken from published measurements of oxygen uptake, or estimated where no study exists, and it covers hundreds of activities, from household chores to competitive sports.

The values describe a typical adult doing the activity in a typical way, and they change between editions. The running values in the ArrayKit table match the 2011 edition, which rates running at 6 mph at 9.8 METs. The 2024 update lists running at 6 to 6.3 mph at 9.3 METs instead, which would bring the 30-minute example down from 360 to 342 calories. To use a newer value, or one for an activity that is not in the table, type it into the calculator's custom MET field.

Why trackers, machines and calculators disagree

A watch, a treadmill and a calculator can give three different numbers for the same workout. The usual reasons:

• A MET value is an average. Fitness, technique, body composition, terrain, wind, heat and anything you carry all change the real energy cost. Two people running side by side at the same speed can use noticeably different amounts.
• Resting rates differ. The formula assumes everyone uses 3.5 millilitres of oxygen per kilogram per minute at rest. Real resting rates vary with age, sex and body composition, so the standard figure can overstate or understate what one person burns.
• Effort labels are broad. In the tool's table, cycling runs from 4.0 METs for leisure riding under 10 mph to 11.5 for 16 to 19 mph. For a 70 kg rider that is 294 calories an hour at one end and 845 at the other, so choosing the level matters more than any other input.
• Wearables measure something else. A watch or band estimates energy from heart rate, movement and the profile you entered. Heart rate also rises with heat, caffeine, stress and dehydration, and wrist sensors can misread during weight training or with a loose strap. Studies that compare trackers with laboratory measurements have generally found their calorie figures far less reliable than their heart-rate readings. The Target Heart Rate Calculator works out the five training zones that many of them display.
• Machines use their own equations. Treadmills, exercise bikes and cross-trainers calculate from speed, incline, resistance or power plus the weight you type in, and some assume a default weight if you skip that step.
• Active versus total. Many watches split energy into active and resting calories. The formula gives the total for the session, so a watch's active figure leaves out roughly the 1 MET of resting energy.

Using the ArrayKit Calories Burned Calculator

The Calories Burned Calculator asks for an activity, your weight and the duration in minutes. Its list has 19 activities, each shown with its MET value, from slow walking at 2 mph (2.8) to running at 8 mph (11.8). It starts on running at 6 mph with 70 kg and 30 minutes, which gives the 360 calories of the first example. Switch on "Use a custom MET value" to replace the list with your own number, such as a Compendium value for an activity that is not listed.

Weight goes in as kilograms (Metric) or pounds (US), and pounds are converted at exactly 0.45359237 kg. The result is one figure, rounded to a whole number and labelled "cal", which here means kilocalories, the calories on food labels. A copy button gives a plain-text summary of the activity, weight, duration and result.

The limits follow from the method. The result is gross calories from the formula above, with no adjustment for age, sex, fitness, heart rate or terrain. It handles one activity at a time, so for a mixed session, work out each part and add them up. Weight, duration and MET must all be greater than 0, or the tool shows an error instead of a result. Everything is calculated in your browser, and the numbers you enter are not sent anywhere.

The figure is an estimate from a standard formula and not medical advice, and a doctor is the right person to ask before you start a new exercise programme.

Frequently asked questions

What does MET mean? MET stands for metabolic equivalent of task. One MET is the energy you use sitting quietly, set by convention at 3.5 millilitres of oxygen per kilogram of body weight per minute, or about 1 kilocalorie per kilogram per hour. An activity rated 5 METs uses about five times that.

How do I calculate calories burned from METs? Multiply the MET value by 3.5 and by your weight in kilograms, divide by 200, then multiply by the minutes. For 45 minutes of brisk walking (5.0 METs) at 80 kg, that is 5.0 × 3.5 × 80 ÷ 200 × 45 = 315 calories.

How many calories does an hour of walking burn? At 3 mph, rated 3.5 METs in the ArrayKit table, a 70 kg person burns about 257 calories in an hour. Brisk walking at 4 mph (5.0 METs) raises that to about 368, and an 80 kg walker at the same pace burns about 420.

Does body weight change the calories burned? Yes, in direct proportion. Thirty minutes of running at 6 mph comes to about 283 calories at 55 kg, 360 at 70 kg and 489 at 95 kg. The MET value stays the same; a heavier body simply needs more energy to move.

Why does my fitness tracker show a different number? A tracker estimates from heart rate, motion and your profile, while the MET formula uses an average value for the activity, so neither is a direct measurement. Some trackers also show only active calories, which leave out the energy you would have used at rest anyway.

Are the calories in the result kilocalories? Yes. Like food labels, the calculator says calories but means kilocalories (kcal). One kilocalorie is 4.184 kilojoules, so 360 kcal is about 1,506 kJ.

Keep going

• Calorie Calculator — estimate daily maintenance calories from your size, age and activity.
• Daily Calorie Needs, Explained — BMR, TDEE and what a calorie deficit means in numbers.
• TDEE Calculator — resting and total daily energy side by side.
• Pace Calculator — solve running pace, time or distance from the other two.
• Body Mass Index, Explained — the BMI formula, healthy ranges and BMI's limits.
• Health calculators — every health and fitness calculator on ArrayKit.

Calculadora de Calorías Quemadas

More guides

• Body Mass Index (BMI), Explained — The BMI formula in metric and imperial units, what a healthy BMI is for adults, the WHO categories, and why BMI is only a screening number with real limits.
• Daily Calorie Needs, Explained — How many calories you need a day: BMR vs TDEE, the Mifflin–St Jeor formula, activity multipliers, and what a 250 or 500 calorie deficit means in practice.
• Pregnancy Due Dates, Explained — How a due date is calculated: Naegele's rule (LMP plus 280 days), cycle length, conception and IVF dates, early ultrasound, and why few babies arrive on it.
• Base64 Encoding, Explained — Base64 explained: how it turns binary into text, the alphabet and padding, the URL-safe variant, size overhead, use cases, and why it isn't encryption.
• Linux File Permissions and chmod, Explained — What chmod 755, 644 and 777 mean: owner, group and others, read, write and execute, octal and symbolic modes, umask, setuid, setgid and the sticky bit.
• DMS and Decimal Degrees, Explained — How to convert DMS to decimal degrees and back, how DD, DMS and DDM differ, how many decimal places you need, and which formats Google Maps and GPS accept.

All Health & Fitness tools · All guides

---