A MET, or metabolic equivalent of task, expresses the energy cost of an activity as a multiple of resting metabolic rate. Sitting quietly is defined as 1 MET; an activity rated at 8 METs burns roughly eight times the energy of sitting still, for the same duration.
This is the standard formula for converting a MET value into an estimated calorie burn, derived from the definition of one MET as 3.5 mL of oxygen consumed per kilogram of body weight per minute, combined with the standard conversion between oxygen consumption and energy expenditure.
Why body weight is central to the calculation
Moving more mass costs more energy, so heavier individuals burn more calories doing the same activity for the same duration than lighter individuals — this is built directly into the formula, since weight is a multiplying factor. This is also why calorie burn estimates from wearable fitness trackers ask for body weight as a setup step; without it, the estimate cannot account for this effect at all.
MET values are averages, not measurements of you specifically
The published MET value for “running at 6 mph” is drawn from studies averaging many people’s measured oxygen consumption at that pace. An individual’s actual energy cost varies with running economy, fitness level, terrain, and even footwear — well-trained runners are often more metabolically efficient at a given pace than untrained ones, meaning they burn somewhat fewer calories covering the identical distance at the identical speed. MET-based estimates are therefore best treated as a reasonable approximation, not a precise individual measurement.
Comparing activities
| Activity | Approximate MET |
|---|---|
| Yoga | 2.5 |
| Walking, brisk | 5.0 |
| Weight training, general | 3.5 |
| Cycling, moderate | 8.0 |
| Swimming, moderate laps | 8.3 |
| Running, 6 mph | 9.8 |
| Jump rope | 12.3 |
| Running, 8 mph | 13.5 |
Where this fits into a bigger picture
Exercise calorie burn is typically a modest fraction of total daily energy expenditure for most people — resting metabolism (see the BMR/TDEE calculator) usually accounts for the largest share of calories burned in a day, even for people who exercise regularly. This tool estimates the exercise contribution specifically, not a complete daily energy picture.