Elliptical Machine

I have been told that the machines read high. I have a MFP friend who does a lot of her cardio work on the elliptical and wears a HRM. She told me that the machines read far higher than the monitor, so, only eat back half of your exercise calories to be safe.
I wear a Fitbit and have the same problem, on a really busy day it can give me 600 calories just for walking around at work, again, I don't eat them all back.
Too late to ask Santa for a HRM?

They definitely read high. I have an elliptical at my house that says I burn half the calories that I do at the gym.

My experience is that the "distances" and calorie burn rates that are displayed on things like elliptical machines are more about marketing than reality. I once used two nearly identical pieces of equipment from different manufacturers and worked out at about the same intensity level on both but one said I was burning calories at literally twice the rate the other did. Nonsense. I use MFP to give me a rough estimate of my calorie burn and leave it at that. Yes, it could be more or less, but I know exactly the time I spent and I have a good sense of how vigorous it was and I use those to let me know how I do tomorrow and that's what I care about.

Some of the machines include the calories that you expend just being alive while on the machine. Others include the calories they expect you to burn in an afterburn effect after having done the exercise. These can make the number much higher as they aren't calories directly attributable to the work you did on the machine at the time. Not exactly dishonest but can be misleading when counting the work in something like MFP.

I'm not finding it now, but there is an interesting study out there done my the US military when they compared different models of elliptical to the actual caloric expenditure so they could normalize the data for use in their fitness evaluation program for people unable to do the semi-annual distance run. Many of the machines showed results that were up to like 30% higher (in my faulty memory) than the caloric expenditure they measured through O2 metabolism.

I'm a 6"3, 260 pounds guy and I do 45 minutes elliptical 5 times a week

Average heart rate of 135 for the duration gives me 700 cal at 120/130 spm.
@125 heart rate average (and easier resistance, about 120 watt) I spend about 620 cal.

the machine ask you for weight and age before starting ?
not all brands use the "right" tables to project energy expenditure...

I got myself a Heart Rate monitor (polar h7, mostly because I had a polar watch) and use it with endomondo on an iphone.
I tried runkeeper and runtastic also but for one the cal expenditure was wayyyy off (might have been corrected) and runtastic is really for the runners, not for elliptical...

In the end it is also an average, but the app also takes into consideration that moving 6'3" takes more energy than moving 5'...

What's your age, weight and height, if I may ? And what is that heart rate limit you use ?
If you are around 360+ pounds and 6'+ it is sort of possible to spend 800 cals in half an hour, but your message would have been "my personal trainer is trying to kill me" 8)

I am 88 kg and use the procor 354 elliptical. I'll do 45 min on level 10 incline and 10 resistance out of 20 on both scales. The machine says I burn 700-750 calories tromping along at about 145 stp per min and keeping my heart rate at 145. I also go as fast as I can for one min at each 5 min mark spiking my heart rate to 180. With all of that I usually take the MFP rate of like 550 calories for the run knowing that the machine over reports.

I'm almost 200 lbs, and I find it difficult to reach the 10 cals a minute mark. You would have to be heavy and working very hard to burn even 400 cals in a half hour.