how accurate are the "Calories burned" counters on cardio equipment?

I'm just curious if they give a pretty accurate reading, or if other factors affect how many calories you actually burn? The reason I'm asking is the elliptical machine at my gym usually tells me I burn around 300 calories in 30 min. But another machine, an arc trainer, that seems very similar to an elliptical tells me that I burn close to 400 cals. in 30 min. It doesn't feel like I"m working much harder, so how can that be?

Re: how accurate are the "Calories burned" counters on cardio equipment?

I do not find them to be accurate, even if I type in my weight.

Re: how accurate are the "Calories burned" counters on cardio equipment?

idk how accurate they are. but i heard somewhere that you should subtract 10% of the total calories burned to find out what you actually burned..... but again, idk how accurate that is either.

Re: how accurate are the "Calories burned" counters on cardio equipment?

I don't know from personal exprerience but I have always heard that they are really not reliable at all.

Re: how accurate are the "Calories burned" counters on cardio equipment?

not reliable at all. Some are off by 50%

Re: how accurate are the "Calories burned" counters on cardio equipment?

Re: how accurate are the "Calories burned" counters on cardio equipment?

get a heart rate monitor. its the best investment i ever made. I'm obsessed with it!

Re: how accurate are the "Calories burned" counters on cardio equipment?

Not very accurate at all. I usually subtract calories from what the machine says. Those weight loss programs (like My fitness pal) I find to be very off as well. The best way to know how many calories you're burning is to use a heart rate monitor.

Re: how accurate are the "Calories burned" counters on cardio equipment?

Re: how accurate are the "Calories burned" counters on cardio equipment?

Re: how accurate are the "Calories burned" counters on cardio equipment?

thanks all! I will get myself a heart rate monitor.