MET Values Explained
A MET — metabolic equivalent of task — is the ratio of an activity's energy cost to sitting quietly. One MET is roughly 1 calorie per kilogram of body weight per hour. Running at 9.5 km/h is 8.3 METs, meaning it uses 8.3 times the energy of sitting still:
Calories = MET × weight in kg × hours
The values come from the Compendium of Physical Activities, a research reference maintained since 1993 and used by essentially every fitness tracker and calculator, including this one.
Calories Burned Chart
For an 80 kg (176 lb) person:
| Activity | MET | 30 minutes | 45 minutes | 60 minutes |
|---|---|---|---|---|
| Walking, moderate (5 km/h) | 3.5 | 140 | 210 | 280 |
| Walking, brisk (6.5 km/h) | 5.0 | 200 | 300 | 400 |
| Jogging (8 km/h) | 7.0 | 280 | 420 | 560 |
| Running (9.5 km/h) | 8.3 | 332 | 498 | 664 |
| Cycling, moderate | 6.8 | 272 | 408 | 544 |
| Swimming, vigorous | 9.8 | 392 | 588 | 784 |
| Weight training, vigorous | 6.0 | 240 | 360 | 480 |
| Yoga, hatha | 2.5 | 100 | 150 | 200 |
Gross Against Net Burn
Most calculators, including this one's headline figure, report gross calories — the total used during the activity. But you would have burned something anyway simply by existing: roughly 1 MET, or 80 calories an hour for an 80 kg person. The net figure, which is what actually adds to your daily expenditure, is correspondingly lower. For low-intensity activity the difference is substantial: an hour of hatha yoga at 200 gross calories is only 120 net.
Why Trackers Overestimate
Wrist-worn devices infer effort from heart rate and motion, and validation studies routinely find errors of 20–90% for activity calories. They are reliable for step counts and for tracking trends over time, and unreliable as a basis for eating decisions. Treating tracker calories as earned food is the fastest way to erase a deficit.
Exercise Is a Poor Weight-Loss Lever
A 500-calorie run is roughly 45 minutes of hard effort; a 500-calorie snack is a muffin and a latte. Exercise is unmatched for cardiovascular health, muscle retention, mood and longevity, and it is a weak tool for creating a calorie deficit compared with adjusting intake. Doing both works; relying on exercise alone rarely does.
Frequently Asked Questions
Does body weight change the calories burned?
Directly and proportionally. A 100 kg person burns 25% more than an 80 kg person doing exactly the same activity, because moving more mass costs more energy.
Does muscle burn more calories than fat?
Yes, but less than commonly claimed — about 13 calories per kg per day against 4.5 for fat. Gaining 5 kg of muscle adds roughly 45 calories a day, not the hundreds often quoted.
What about afterburn?
Excess post-exercise oxygen consumption is real but small — typically 6–15% of the workout's calories for intense sessions, and close to zero for moderate ones.