Press fits are very difficult, so my simple answer is don't even try. If the kerf is right at 10 mils, specifying 0.490" should get you exactly half an inch, but the kerf is not completely predictable, so I'd recommend going a few mils less, and then possibly enlarging the hole manually as necessary.
If you really need the press fit to work (e.g. if you need many of your part or your part has many holes), you could have us cut a test pattern, first. You could include many different holes and test which works best for you. If you go that route, you should have several of each hole so that you can get some sense of the variation from hole to hole. You might also consider non-circular designs.