Three quarter
Thee-quarter shell helmets probably are the most popular design, providing a good level of protection while not being too warm to wear on milder days. On colder days, skiers often can use included ear flaps with many three-quarter fit helmets. Measure your skull with a flexible measuring tape about two finger's width above your eyebrows, then consult the manufacturer's sizing chart to see your size. Next, try on the helmet to make sure that the front is two fingers above the eyebrows and that the foam does not have any pressure points.
Full helmets
Full helmets have greatly increased in popularity. These helmets are warmer, making them a boon on cold days, and cover the skull completely down past the ears to the jaw line. Some of these helmets also have vents to assist in keeping the skier or snowboarder cool on warmer days. When trying on a full helmet, first measure your skull with a tape measure right above the eyebrows and check the manufacturer's recommendation for the fit. Next, try on the helmet. The padding should fit snugly around your head; check this by shaking your head up and down and from side to side to see if the helmet rattles around. A loose helmet will not provide the required protection.
Full face helmets
Full-face helmets are a variation on a BMX bicycle helmet and are for the skier or snowboarder whose motto is "Go big or go home." These helmets also are recommended for skiers who like to spend a lot of time in the trees skiing hard and fast. The added protection around the face and jaw also is appreciated by many racers. Full-face helmets fit the same way full-shell helmets do. Measure your head circumference right above your eyebrows and check the measurement against the manufacturer's recommendations. Try on the helmet and check to make sure the padding is flush against your head all around and the helmet doesn't move when you shake your head side to side or up and down.
