MFP Calorie Burn #'s vs HRM calorie Burn #'s

I burn much more than what mfp says I do. mfp is just an average so it's only accurate for some.

Because it depends on so many factors - your weight, how hard you work etc

This. There are so many factors into how many calories a person burns - two people of the same height/weight can burn different amounts doing the same activity. It is because our bodies all work just a little differently.

Yep totally, MFP used to overestimate mine by about 200-500 per hour of exercise, it used to say I would burn 1000 cals when my HRM said like 550!

Yep totally, MFP used to overestimate mine by about 200-500 per hour of exercise, it used to say I would burn 1000 cals when my HRM said like 550!

Yes! I recently got a HRM and it was half of what MFP said. So, in the past weeks when I'm eating all my burn calories back, well... that can explain alot! LOL

This is the reason I really want a HRM. I am so close to my goal that any discrepancy can seriously make an impact on my weight loss. I guess I could just not eat my exercise calories back, but that is hard.

I always found the machines and MFP to be fairly accurate compared to the HRM on my Garmin -- but I (generally!!) weigh 160.

Depending on the Garmin, they may indeed be inaccurate.

The Forerunner series for instance does NOT base calories burned on HR at all, but the same types of tables MFP uses for weight and avg speed.

To test yours, start a session and leave it on while taking a car ride. It was that accidental usage and huge calorie burn that told me something was way off.
Indeed, no HR used in calculations, just avg speed.

Other of their models do use the HR, some do a combo, just in case you leave the HRM off, you still get a calorie estimate.

For those getting a HRM, at least read the manual and get one that requires entering sex, weight, age or birthdate, resting heart rate would be great, as well as your own max HR. If really used in calcs, makes it much more accurate.