Determining a Housecleaning Charge?

I need some advice on what to charge to clean/dust a 5000 square foot five-bedroom four-and-a-half bath house, with two kitchens. I need to mop and vacuum the floors. The showers are all glass top to bottom. They just moved in about 5 months ago so it's not really dirty. They only use two bedrooms and two bathrooms. They just want the house cleaned before the holiday.