How this calculator works
Every activity in the list has a metabolic equivalent, or MET, from the Compendium of Physical Activities. One MET is the energy used while sitting quietly, about 3.5 mL of oxygen per kilogram of body mass per minute. An activity at 8 METs uses about eight times that energy. The calculator converts the MET value, body mass and duration into calories, then converts the result to kilojoules for the second display. MET values describe typical participants doing the activity at a typical pace; fitness, technique, terrain and effort can move the true value substantially. Compare mode applies the same duration and body mass to both activities, so the difference isolates the intensity.
Formula
kcal/min = MET x 3.5 x body mass (kg) / 200. Total calories = kcal/min x minutes. In compare mode the difference is the second activity's total minus the first activity's total for the same duration.
Worked example
An 80 kg person walks for 60 minutes at 3.5 METs: 3.5 x 3.5 x 80 / 200 = 4.9 kcal/min, or 294 kcal. The same hour running at 9.8 METs gives 13.72 kcal/min, or 823 kcal, a difference of 529 kcal. In kilojoules those totals are about 1,230 kJ and 3,444 kJ.
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Frequently asked questions
What does MET mean?
Metabolic equivalent of task. It compares an activity's energy cost with resting metabolism. Sitting quietly is about 1 MET; sleeping is about 0.95; running at 6 mph is about 9.8.
Why do two people get different totals for the same activity?
Body mass is the main factor in this model, because moving more mass costs more energy. Fitness and efficiency matter too, but MET tables already average across participants, so the result is an estimate.
Does this include the calories I would have burned anyway?
The MET approach gives gross energy use, including resting metabolism for the same period. The extra energy attributable to the activity is roughly one MET less per minute.