Calculating how much home I can afford – credit card question?

At sites like this: http://money.howstuffworks.com/framed.htm?parent=mortgage.htm&url=http://interest.com/calculators/afford-borrow.shtml
they have calculators to see how much home you can afford.

I am trying to figure out what to enter for the “credit card liability.”

I have never carried a balance on a credit card. So technically I have no credit card “debt.” But I use credit cards for EVERYTHING (almost never use cash), so every month I have over one thousand dollars to pay to my credit cards.

What is the right way to calculate — do they want the amount I am “in debt” (zero) or the average of my monthly credit card bills (over one thousand dollars)? I feel that the latter figure may not accurately represent my actual financial situation, since if I used cash instead of credit cards I could enter “zero” — I just use the cards to earn rewards.

Maybe the real question is — how will the banks calculate it?