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Calories Burned Calculator
Choose an activity, enter your body weight and how long you did it, and get an estimate of the kilocalories burned using the metabolic equivalent (MET) method, with values from the Compendium of Physical Activities.
What a MET is and how the estimate works
A metabolic equivalent of task (MET) expresses the energy cost of an activity as a multiple of resting energy use. Sitting quietly is 1 MET, which is taken as about 1 kilocalorie per kilogram of body weight per hour. Brisk walking at 5 MET therefore uses about five times as much energy as resting. The estimate is then straightforward:
Calories = MET × body weight (kg) × time (hours)
For a 70 kg person running at 8.3 MET for half an hour this gives 8.3 × 70 × 0.5 = 290.5 kcal. The calculator also shows a net figure, (MET − 1) × kg × hours, which removes the energy you would have used anyway. Which number is more useful depends on whether you are comparing against doing nothing (net) or against a day total (gross).
Where the MET values come from
The values in the menu come from the 2011 update of the Compendium of Physical Activities by Ainsworth and colleagues, which assigns a MET value to hundreds of activities based on measured oxygen use in studies. Only activities with well-known values are listed. If yours is missing, choose the custom option and enter a MET value from the Compendium or from a source you trust. Values refer to a defined pace or effort, so a casual cycle ride and a hard training ride have very different METs.
How accurate is it
- Individual variation: fitness, body composition, age, sex, efficiency and the weather all affect real energy use. The MET method assumes an average person.
- Intensity: the biggest source of error is picking a MET that does not match your actual effort. Running at 6 mph versus 5 mph changes the answer by almost 20%.
- Devices: wearable watches also estimate calories and can differ from MET calculations by large margins in either direction.
- Resting energy: the standard MET of 1 equals 3.5 mL of oxygen per kg per minute, which overstates resting energy for many adults, so the gross figure may run high.
Treat the output as an estimate within perhaps 10 to 30 percent rather than a measurement.
Using the figure sensibly
Do not eat back every calorie an estimate shows. Estimates of burn tend to be generous and portions of food are easy to underestimate, so using the number to justify extra snacks can erase the effect. For weight goals, the calorie balance over weeks matters, and the calorie calculator estimates daily needs. Anyone with heart disease, high blood pressure, joint problems, pregnancy or a long break from exercise should check with a clinician before starting vigorous activity. This page is educational and not medical advice.
Worked example
A 70 kg person runs at 5 mph (8 km/h) for 30 minutes.
Inputs
| Body weight | 70 |
|---|---|
| Weight unit | Kilograms |
| Activity | Running, 5 mph / 8 km/h (8.3 MET) |
| Duration | 30 minutes |
Result
About 256 kcal of that is above what you would have burned at rest.
| MET value used | 8.3 |
|---|---|
| Body weight | 70.0 kg |
| Time | 30 minutes (0.50 hours) |
| Gross energy (MET x kg x hours) | 291 kcal |
| Net of resting energy ((MET - 1) x kg x hours) | 256 kcal |
| Per hour at this effort | 581 kcal |
- One MET is the energy cost of sitting quietly, taken as about 1 kcal per kilogram of body weight per hour.
Medical disclaimer: This tool is for education and general planning. It is not medical advice and does not diagnose any condition. If you are pregnant, under 18, have an eating-disorder history or a medical condition, speak to a doctor or registered dietitian before changing your diet or exercise.
Frequently asked questions
How do I calculate calories burned?
Multiply the MET value of the activity by your body weight in kilograms and by the time in hours. A 70 kg person doing a 5 MET activity for one hour burns about 350 kcal.
What does MET stand for?
MET means metabolic equivalent of task. One MET is the energy cost of sitting at rest, so a 6 MET activity costs about six times that rate.
Why does my watch show a different number?
Wearables use heart rate, motion and a profile of your age and weight, and not the MET table. Both methods are estimates, and they can differ by tens of percent.
Does a heavier person burn more calories?
Yes, for the same activity and time, because moving more mass costs more energy. That is why body weight is part of the formula.
What is the difference between gross and net calories?
Gross calories include the energy you would burn at rest during the activity. Net calories subtract that resting amount, showing only the extra energy the activity costs.
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References and sources
- Ainsworth BE, et al. (2011). 2011 Compendium of Physical Activities: a second update of codes and MET values. Medicine and Science in Sports and Exercise 43(8):1575-1581. Link
- American College of Sports Medicine (2021). ACSM Guidelines for Exercise Testing and Prescription, 11th edition.