By and large, most shower curtains come measuring approximately 72 x 72 inches, with the occasional variation around this. As Omni Home Ideas' interior buff, Brad Smith, puts it, "This size typically works well for standard bathtubs and showers." Chances are, this will work perfectly for the average renter or dorm-dweller's bathroom, but there's no harm in checking. A simple measure of your tub and shower should set you straight. "If you have a larger shower or a custom-sized shower, you may need to look for extra-wide or extra-long shower curtains," adds Smith. Fortunately, there's plenty more to choose from — just see some of the top retailers listed below.