(1) The length of the hose is measured at its theoretically full extension. However, the hose never actually reaches this full extension because of elastic resistance (i.e. the very same "spring" effect which is the reason you presumably bought the hose) and torsion along the length of the hose as it is stretched. My experience is that you lose approximately 25% of the hose's length to these two effects. The only way to beat this is by making sure that the hose's rated length is that much LONGER than you need.
(2) Make sure that you have the appropriate adapter permitting you to attach the hose to your faucet. Designer faucets, faucets with hose attachments, imported faucets, and outdoor faucets all may have trouble working with this hose out of the box.