Ski Boot Sizing and Fit Guide

How ski and touring boots are sized, how to find your size at home, and what to expect when you come in for a fitting at the shop on F Street.

Boots are sized in Mondopoint

Ski boots use Mondopoint, which is simply the length of your foot in centimeters. A 27.5 boot is built for a foot about 27.5 cm long. Mondopoint has nothing to do with your sneaker size, and most people who size off their street shoes end up a full size too big. Shells are made in whole sizes only, so a 27.0 and a 27.5 share the same shell and differ only in liner thickness.

Measure your foot

• Stand on a piece of paper in a thin sock with your heel against a wall. Mark the end of your longest toe.
• Measure heel to mark in centimeters. Do both feet and use the longer one.
• Measure the widest part of your forefoot. This picks your last width, which matters as much as length.

Last width

Last is the width of the shell at the forefoot, in millimeters, for a reference size 26.5. Narrow feet fit a 97 to 98 mm last, average feet a 100 to 102 mm last, and wide feet 103 mm and up. Touring boots like the Scarpa Maestrale and Gea run about 101 mm. The Dynafit line runs a bit narrower. A boot that is the right length but the wrong width will never feel right.

Flex

Flex is the stiffness of the cuff. Numbers are not standardized between brands, but as a rule of thumb: 80 to 100 for newer or lighter skiers and long days on the skin track, 100 to 120 for most experienced skiers, 120 and up for aggressive skiers and heavier riders. Touring boots feel softer in walk mode and stiffer once locked, so compare them to each other, not to alpine boots.

Touring boot soles and binding compatibility

Backcountry boots need tech inserts (the metal fittings at the toe and heel) to work with pin bindings like ATK, Dynafit and Atomic Backland. Hybrid bindings like the Atomic Shift need a boot with tech inserts and a GripWalk or Touring sole. Telemark boots are a separate system: 75 mm duckbill for 3-pin and cable bindings, or NTN for 22 Designs Outlaw and Lynx. If you are not sure what your bindings take, send us a photo and we will tell you.

How the fit should feel

• New boots feel snug everywhere, with toes brushing the end when you stand upright and pulling back when you flex forward.
• No heel lift when you flex. Heel lift is the number one cause of shin bang and blisters.
• Pressure points on bunions, ankle bones or the sixth toe are fixable with a punch or grind. Numbness or cramping across the whole foot usually means the shell is too small or too narrow.
• Liners pack out 5 to 10 percent in the first ten days. A boot that is comfortable on day one in the shop will be loose by February.

What a fitting at the shop includes

We measure both feet, check your arch and ankle flex, and do a shell fit with the liner out so you have the right amount of room. We then heat mold the liner, build custom footbeds if you want them, and punch or grind any pressure points. Plan on an hour for new boots. Custom footbeds are $175, liner molding is $60 (half off with a full price boot purchase), and punches and grinds run $35 to $50 per spot. Read what to expect at a boot fitting.