When choosing the correct size ski boot you also need to consider your skier profile. Ski boot manufacturers have designed boots specifically for beginner, intermediate or advanced use. For example, the hard plastic outer shell differs by your profile; soft shells are designed for beginners, stiff shells are designed for intermediate/advanced use and very stiff boots are designed for professional level skiers. Make sure you check the recommended size for your ski boot model. Important: please check sizing for individual ski boot models. This chart is a general guide and sizes may vary slightly by ski boot manufacturer. If you are looking for more information about alpine ski boots, check out the Ski Boot Buying Guide from REI.com.