Calories Burned Calculator

How exercise energy cost is measured

Exercise energy cost is usually expressed in METs, short for metabolic equivalents. One MET is the energy you use sitting still, about 1 kcal per kilogram per hour. Walking at 3 mph is about 3.5 METs, jogging is about 7, running at 6 mph is about 9.8 and jumping rope is around 12. The Compendium of Physical Activities catalogues these values for hundreds of activities.

The formula is simple: kilocalories = MET x 3.5 x body weight in kilograms / 200 x minutes. The 3.5 and the 200 are unit conversions, not physiology. The practical consequence is that body weight and duration dominate the result: a heavier person burns more for the same session, and twice the duration means twice the energy.

What the calculator reports

The output gives total calories for your session, then scales it to a per-minute figure, a 30-minute figure and an hourly figure, so you can compare activities of different lengths on the same basis. It also reports how long you would need to continue to burn 500 kcal, which is the figure most food comparisons implicitly use.

The fat-equivalent row converts the session into pounds using 3,500 kcal per pound. Read it as an energy equivalence, not a prediction: the body does not burn a straight line of fat during or after exercise, and the calorie figure is a gross expenditure that includes the energy you would have burned anyway just being alive.

Why the number is lower than your watch says

Most wearables report gross energy expenditure for the whole day, including resting metabolism, and their exercise algorithms add an 'active calories' figure that often runs 10% to 30% high. The gap is largest for strength training, where heart rate stays moderate while the actual oxygen cost is high, and for short intervals, where heart rate lags behind the work.

There is also a real physiological reason the session figure overstates the net effect: you would have burned roughly 1 MET of energy during that half hour anyway. A 386 kcal run at 9.8 METs is about 347 kcal above what sitting still would have cost. That net figure is the one that matters if you are trying to decide what a session is worth.

Using the numbers without over-eating them

The most common error is adding back the full exercise figure to a calorie target that was already calculated with an activity multiplier. If your TDEE already assumes three to five sessions a week, that training is paid for; logging it again as an extra 400 kcal is double counting, and it is a reliable way to lose no weight while being sure you are in a deficit.

A workable rule: keep intake stable and let training shape body composition rather than the calorie budget. If a session is genuinely exceptional - a two-hour hike, a race, a long ride - eat something extra on the day.

• Do not add the full session figure on top of an activity-adjusted target.
• Treat the calculation as gross expenditure, not net.
• Use it to compare activities, not to justify a reward meal.
• For weight loss, food changes move the needle faster than exercise does.

Where exercise genuinely helps

Exercise is a poor tool for creating a large deficit and an excellent tool for everything else. It protects lean mass during a cut, raises daily energy expenditure through the steps and activity that come with being fitter, improves insulin sensitivity, blood pressure and mood, and it is the main lever on body composition rather than body weight.

The energy cost of the session itself is often the smallest part of its effect. People who train regularly tend to accumulate 2,000 to 4,000 additional steps on training days and keep more muscle as they age, and those two things are worth more over a year than the 380 kcal in the session itself.

Frequently asked questions