Calories Burned Calculator
What a session actually costs you, by activity and bodyweight. Based on published MET values, not a fitness tracker’s optimism.
The same hour, different activities
| Activity | 60 minutes |
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Calories are estimated as MET multiplied by body weight in kilograms multiplied by hours, using the Compendium of Physical Activities. Real burn varies with fitness, intensity and efficiency, and most wearables overestimate by twenty to forty percent on resistance training. Treat this as an honest ballpark rather than a bank balance. General fitness information, not medical advice.
How many calories does a workout actually burn?
Less than you think, and less than your watch says. That is not a reason to train less — it is a reason to stop treating exercise as a way to buy back food. Training builds the body. Eating decides the weight. Once you accept that, both jobs get easier.
How the number is calculated
This uses MET values from the Compendium of Physical Activities, the reference set researchers use. One MET is what you burn sitting still. Heavy weight training is about six, so for one hour you burn roughly six times your resting rate. The formula is MET multiplied by your body weight in kilograms multiplied by hours. A bigger body burns more doing the same work, which is why body weight is in the equation.
Why your tracker is wrong
Wrist devices estimate burn from heart rate, and heart rate is a poor proxy during resistance training — a heavy set spikes your pulse without the oxygen cost that would justify it. Independent testing has repeatedly found overestimates of twenty to forty percent on lifting sessions. If you eat back what your watch says you burned, you will stall.
The honest maths of fat loss
A pound of body fat is roughly 3,500 calories. A hard hour in the gym might be 600. Four of those sessions a week is 2,400 — useful, but it is about two thirds of one pound, and a single large restaurant meal can erase most of it. The deficit that actually works comes from the kitchen, with training there to make sure the weight you lose is fat and not muscle.
So what is training for?
Keeping the muscle you have while you diet. Raising your resting burn over years by adding lean tissue. Improving how your body handles carbohydrate. Giving you a reason to sleep and eat properly. The calories are a side effect, not the point.
Common questions
Does lifting burn more than cardio? Not during the session. Over years it does more for your metabolism, because it adds tissue that burns calories around the clock.
What about the afterburn? Real but small — typically six to fifteen percent of the session for intense work, not the hundreds of calories often claimed.
Should I eat back exercise calories? No. Set your intake from your total daily burn with training already included, then leave it alone.
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