? Deep Cleaning the House ?

I do not count my normal cleaning like dishes and laundry, but if I spend a large amount of the day moving furniture and vaccuming, mopping, etc. I usually put it in to see how many calories I will burn. Again I need to get an HRM, but how accurate are the calculators with MFP? It said for the two hours I just did (and I am sweating my butt off)... I burned 515. Who keeps with what they say or who changes it ? Thanks a bunch