Finding the correct fit for your boot is crucial. Kenetrek Pac Boots are available in whole sizes only and are sized to incorporate a good quality boot sock. If you wear a half size, round up to the next whole size. The Kenetrek Mountain Boots run very true to size with the Brannock device, which is the steel measuring instrument found in shoe stores and the standard for American shoe sizing. Many customers choose to go up a half size from their street shoe size to allow for a little extra toe room - vital for going downhill especially with a backpack in the mountains.