Calories Burned Calculator
How many calories an activity burns, for your weight and how long you do it.
Good to know. A 30-minute run burns about as much as a large muffin has, which feels unfair to the run.
Approximate. Real-world values vary.
How it works
In plain words
Each activity has a MET value: how many times more energy it takes than sitting still. One MET is about 1 kcal per kilogram of body weight per hour, so multiply the MET by your weight and the hours.
The formula
calories = MET × weight in kg × hours 1 kcal = 4.184 kJ
Worked example
Running at 6 mph has a MET of 9.8. For a 70 kg person for 30 minutes: 9.8 × 70 × 0.5 = 343 kcal.
Sources
- Ainsworth et al., 2011 Compendium of Physical Activities, Medicine and Science in Sports and Exercise MET values for each activity.
Sources checked September 30, 2026. 2 automated tests check its answers on every change.
About the calories burned calculator
This calculator estimates the energy you use during an activity, from how hard the activity is, your body weight and how long you do it. Heavier people burn more for the same activity, because they move more mass.
The effort of each activity is measured in METs, metabolic equivalents. Sitting quietly is 1 MET, about 1 kcal per kilogram of body weight per hour. Brisk walking is about 4, running at 6 mph almost 10. The values come from the Compendium of Physical Activities, the reference researchers use, which measured hundreds of activities.
The numbers are averages. Fitness, technique, terrain, wind and heat all change the real figure, and fitness trackers can be just as far off in either direction. The result includes the energy you would have used at rest anyway, roughly 1 kcal per kg per hour, so the extra burn from exercising is a little less.
For weight loss, exercise helps, but it is easy to eat back: a 30-minute run burns about as much as a large muffin or a latte and a biscuit. Combining activity with a modest calorie deficit works best; the calorie deficit calculator shows how much to eat.
Questions people ask
How many calories does walking burn?
About 4.3 kcal per kg per hour at a brisk pace: roughly 150 kcal for a 70 kg person walking for 30 minutes.
How many calories does running burn?
Roughly 1 kcal per kg of body weight per kilometre. A 70 kg person burns about 343 kcal in 30 minutes at 6 mph.
What is a MET?
A metabolic equivalent: how many times more energy an activity uses than sitting still. 1 MET is about 1 kcal per kg of body weight per hour.
Are fitness tracker calories accurate?
Often not very. Studies find errors of 20% or more for energy use, even when heart rate is measured well.