# Calorie counter on an exercise machine is it actual or approximation?

On any machine that gives you the amount of calories burnt, is the calorie count actual or approximation based on weight / effort?
If it is an approximation, any idea on what would be the average +/- error range? Or is it too negligible to even consider it even when using it for 1000 calories?

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– arober11 Jul 21 at 9:22

It's an approximation based on some formulas. It assumes muscle/fat based off of simple BMI calculations (which is not always typical), and depending on the speed/intensity predicts what an average person at your body weight would be burning based.

More advanced formulas that you'll find in your heart rate monitors take into consideration your heart rate to fine tune the intensity. It still considers what you tell it your weight is.

All that said, it is a useful approximation to judge the relative effectiveness of an exercise for burning calories.

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I'd only say relative to different programs on the same machine. You can't compare the calorie counts between machines because of all the variables you mention. – Christopher Bibbs Jul 6 '11 at 15:31
Agreed. For the same reason (differences in algorithms) you can't compare Calorie counts across different brands of the same type of machine either. I.e. the Calorie counts for two brands of treadmills will be different. – Berin Loritsch Jul 6 '11 at 15:37

Approximation !!!!! There's absolutely no practical way for any machine to state your actual calorie consumption, and they're aren't even any vaguely accurate regression equations, without data from an ECG and face mask based gas analyzers, to estimate the KCals burnt. Though machine manufacturers try, though the figures can be as much as +/- 40% off.

Note: The Kcal values on food packaging, where you can scientifically measure the values, legally only have to be accurate to +/- 20%.

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It's an estimate (based on standard-issue formulae) of total calories burned during the period you are on the machine. The key word here is total calories; that is, you might typically burn 90% of what the readout shows with your basic metabolism (i.e. laying on the couch). The readout doesn't specify what percentage is specifically due to your activity on that machine.

The brutal truth is that there are not very many people physically capable of burning 1,000 calories due to the activity alone in one session.

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