If you don’t know your tire size, it will be in the owner’s manual, the driver’s side door jamb, or on the side of the tires as a series of letters and numbers. The number you’ll need is after the R, which is the diameter of your rim in inches.
For exmaple, if the tire size on your Chevrolet Cavalier is P195/65R15, the rim size is 15 inches.
You can purchase a set of aftermarket rims for your Chevrolet Cavalier on Amazon for as little as $60, but branded ones will cost more.