How do you count calories burned?

I just recenlty bought a fitness watch, that takes your heart rate and determines how many cals burned during workout. I must say this number is significantly higher than those shown either on the machine I am working out on or the cals logged in the MFP workout database. I have heard that the watches/chest monitors are more accurate. But to some degree I feel weird about over-riding the calories shown or in the database, to indicate what the watch is telling me. My husband says Im being weird about the whole thing, but how do I know that my watch isnt broken. lol ...

So what do you do? Do you use the MFP database, do you use the treadmill number, or go off of your personal device?