4qts. Run the car for a bit to make sure all the oil has circulated into the new filter, pull the dipstick out and then put a mark on where the oil line hits. Dipstick is now marked at the right level.
PS - Do all this on a nice level surface. I also like to fill up my oil filter before re-installing, let it sit a few minutes then top it up again. If you do it this way just make sure the total oil used is 4 qts.