Calories Burned Formula: MET x Weight x Time Explained

Calories burned estimates are not magic. Most activity calculators combine a MET value with your body weight and time. Once you understand that formula, you can see why pace, intensity, and body size change the result.

The MET Formula

One MET approximates resting energy expenditure. Activities are assigned MET values based on observed intensity. A slow walk may have a low MET value, while running, cycling hills, or vigorous circuit training receives a higher value.

A widely used equation is calories = MET x 3.5 x weight in kilograms / 200 x minutes. This turns intensity, body mass, and duration into estimated kilocalories.

Why the Same Workout Burns Different Calories

Two people can do the same 30-minute workout and see different calorie estimates because body weight changes the energy cost. A heavier body generally requires more energy to move through the same activity.

Fitness level also matters. As efficiency improves, the same pace may feel easier. A calculator estimates population-average energy cost, while wearable devices add heart-rate and movement sensors that may still have error.

• Intensity: faster pace or higher resistance raises MET value.
• Duration: doubling time roughly doubles estimated calories.
• Body weight: kilograms are part of the formula, so weight changes the result.

How to Use Calorie Estimates for Training

Use calorie estimates as planning ranges. They are helpful for comparing activities, estimating weekly activity volume, and building a calorie target alongside BMR and TDEE. Avoid treating a single workout estimate as an exact number to eat back.