Garmin 610 Calories

So...first I'll say that no, I am not counting my calories and I don't usually pay attention to that setting on my GPS watch. But I find it interesting that, though I have the exact same user profile (height, weight, age, etc.) on my 610 as I had on my 305, the calories burned are significantly different. They are basically half. (e.g., Whereas with my 305 it would say I burned 100 for a mile, on the 610 it says 50, or something like that)...

I have done all of the software upgrades. Anyone know why this is? Again, I don't care for any tracking purposes. Just a curiosity as I obsess over my new toy.

Well, obviously, the calculations take into account how much smaller and lighter the 610 is compared with the 305.

Did you have your correct weight in both toys?

I think the 605 does calorie calculations based on HR, if I'm not mistaken. Also, could be the net calorie burn or the total burn (the latter would included your BMR, the former would not).

So, what have we learned? Anybody watching their weight should definitely go with the 305.

The 305 uses a weight / distance calculation.
The 610 uses heart rate base calculation.

The 610 is clearly too low, but the 305 is generally too high.

I think that the 305 is closer.