How calories burned are estimated
Every activity has a MET value (metabolic equivalent of task): how many times more energy it uses than sitting at rest. Sitting quietly is 1 MET, brisk walking about 5 and running at 6 mph about 10. The calories burned are MET × body weight in kg × hours, so a heavier person burns more doing the same thing.
Example: a 160 lb (72.6 kg) person running at 6 mph (9.8 MET) for 30 minutes burns about 356 Calories. Walking at 3 mph for the same time burns about 127.
Where the numbers come from
The MET values are from the Compendium of Physical Activities, a research list used by exercise scientists. They are averages: fitness, effort, terrain and even the weather change what you really burn, so treat the result as an estimate, usually within 10% to 20%.
Burning more
- Raise the intensity: the same 30 minutes burns far more at a run than at a walk.
- Add strength training; muscle raises the calories you burn at rest.
- Move more through the day: walking, stairs and chores add up.
Frequently asked questions
Are fitness tracker numbers more accurate?
Trackers use your heart rate as well, which helps, but studies show they can still be off by 20% or more for calories.
Does this include the calories I would burn anyway?
Yes, it is the total during the activity, including your resting burn. The extra from exercise alone is about (MET − 1) × weight × hours.
How many calories make a pound of fat?
About 3,500. Burning an extra 500 Calories a day, through exercise or diet, adds up to about a pound a week.