....and whether or not it will fit on the car is a whole other issue; test fitting is about the only way to be certain. That's why it helps to have a good relationship with a good wheel/tire store -- so they can help you make the best guess, and then help you test fit.
I just went through this on mine -- VERY limited room in the back and I wasn't sure that I could go up in size. So we test fit a larger tire on my wheel just to be sure. It all worked out -- but I wouldn't have known for sure without the test fit.