Hose size addresses two important factors—length of the hose and the inside diameter. Air hoses typically come in 25-, 50- or 100-foot lengths, and all have their advantages and disadvantages. If you're only going to use it to air up tires in a small garage, 25 feet might suffice. But a 50-foot hose is much more versatile, and a 100-footer is even more so. Buying a hose that is too short is a lot more trouble in the long run than having one that is too long. But a hose that is too long will leave you with more rolling and storage problems. Concerning diameter, most hoses are either 1/4 or 3/8 inch. In general, 1/4-inch hoses are lighter, less expensive and easier to roll up and store. Wider hoses, on the other hand, limit frictional loss. So, if you're using a tool that needs every bit of air you can get to it, a 3/8-inch air hose is the better bet.