Calories Burned Calculator

How calories burned is calculated

The estimate uses MET values, where MET stands for metabolic equivalent of task. One MET is the energy you burn sitting quietly; an activity rated at 8 METs burns about eight times that much per minute. Each activity is assigned a MET value from the Compendium of Physical Activities (Ainsworth et al., 2011), a published reference that catalogues hundreds of activities by intensity. The formula is calories = MET x bodyweight in kilograms x hours, so both how hard you work and how much you weigh drive the result.

For example, running has a MET of about 9.8. An 80 kg person who runs for 30 minutes burns 9.8 x 80 x 0.5, which is roughly 392 calories. The same person lifting weights (about 5.0 METs) for the same half hour burns 5.0 x 80 x 0.5, or about 200 calories. That gap shows why steady running clears more calories per minute than a typical weights session.

Why bodyweight changes the number

Moving a heavier body costs more energy, so two people doing the identical workout burn different amounts. A 60 kg person running for 30 minutes burns about 294 calories, while a 100 kg person burns about 490 calories doing exactly the same run. This is why generic charts that quote one calorie figure per activity are misleading: the figure only applies at the bodyweight it was calculated for. Entering your own weight gives a far closer estimate than a one-size-fits-all table.

How accurate is the estimate

MET-based numbers are solid ballpark figures, but treat them as estimates rather than exact readings. Real energy expenditure shifts with intensity, fitness, terrain, technique and body composition, and can differ from the calculated value by 10 to 20 percent. A fitness watch or chest-strap heart rate monitor can give a more personal reading. One more caution: if you already use a TDEE or maintenance-calorie figure that includes your training, do not add all of these calories back on top of your food, or you will cancel out your deficit.