Slot cars come in a wide variety of sizes, but probably the most traditional and well-liked slot automotive measurement is the 1:32 scale. The "0 scale" is the standard measurement of model trains, which then grew to become the comparison measurement for the HO scale slot automobiles. This scale signifies that for every 1-inch (2.Fifty four centimeters) on the slot automotive there are 32 inches (81.28 centimeters) on a full dimension car.