How To Choose Downhill Ski Boots

The right pair of ski boots unlocks the athletic potential in your skiing. Choosing a boot is a process that involves a number of factors in selecting one that matches ability and ambition. Foot shape, prior injuries, stiffness of the shell, and intended use, all come into play, and blindly selecting a pair will inhibit the ability of a beginner or advanced skier. This guide explains the details that go into choosing the perfect pair of downhill ski boots.


Ski boots have a two-layer construction: An outer hard shell, and a softer inner liner. Depending on how aggressively the skier charges the downhill, the hard shell allows a certain amount of flexibility. The number that's stamped on the boot represents the flexibility rating. A lower number represents a softer boot, preferred by a recreational or beginner skier, while a higher number is stiffer, built for those who ski steep lines, freestyle, or executes minute and perfect control. Beginners should look for a flex rating of 50-80, while intermediates prefer 80-100, and expert skiers should have a boot of 110 and higher. Racing boots have a stiffness rating of 130 and above.

The inner liner serves several purposes: It absorbs shock, keeps the foot warm, and protects the foot against the plastic hard shell. Recreational skiers who want to feel comfortable and walk around in their boots all day prefer a plushier, softer liner, while a hard-charging expert skier prefers a version that is less pliable and more performance-driven that they'll use to hike up their lines. These stiff liners have a tighter grip around the heel to keep it locked. Some boots equip a heat moldable Intuition liner. The Intuition liners come in several models, some which include natural thermal molding right out of the box, while others require professional equipment to heat then mold the material to the shape of the foot. The inner sole of the liner is cheaply made, mass-produced, and stiff. Given the opportunity, replacing the inner sole with custom footbed ensures a fully customizable fit.

downhill ski boots

The last is the shape of boot, and this is essential in determining which boot fits the right foot shape, measured in the width of the forefoot. There are boots for narrow, average, and wide widths, each catering to the needs of the skier. A narrow boot is circa 97-millimeters across the forefoot, an average size around 100-millimeters, and a wide boot from 102-millimeters and above. When determining the size, measure at the end of the day when the foot is at its most swollen, and take into account bunions, bone spurs, and prior injuries to determine the exact width. Measure in both sitting and standing positions to take load bearing into account. 

Ski boot sizing How to measure your foot for ski boots


There are notable differences between the size of a ski boot and a street shoe. While the street shoe allows space for comfort, the ski boot is tight and athletic fitting so that the foot has full control over the binding. Boots are measured in Mondo Point size, or the length of the foot in centimeters. To find your Mondo Point length, stand up straight with your ankles against the wall, and assume a relaxed position so that the toes are fully flattened. Measure with a ruler or tape measure from the wall to the tip of the longest toe. The measurement in centimeters is the Mondo Point size. If the measurement is 25 centimeters, then the boot is a size 25. The toes should be touching the front of the boot, but not crunched or folded over. Again, measure in the late afternoon or early evening, when the foot is more swollen. Mondo sizing differs between manufacturers. While one manufacturer may offer a 26.5 and another a 26, these are both the same size. There are no true ski boot half sizes.

Check out this video for more tips on How to Fit a Ski Boot.

Mondao Size Mondo Size Chart


There are three main types of downhill boots: Alpine, Telemark, and Alpine Touring.

Alpine boots are the standard for downhill skiing with a minimally flexible shell and a solid un-textured sole. They're best for resort style in-bound skiing as a softer boot, while an ultra-stiff boot is for fast and aggressive ski racing.

Telemark boots are compatible with telemark-specific bindings. The toe-point is elongated to allow for forward motion, and the boots feature a hinge at the ankle so the rider has greater kick and propulsion.

Alpine Touring boots fit in standard alpine bindings and are meant for hiking to ski lines, climbing, and glacier travel on and off the skis. AT Boots feature rubber textured soles, stiff linings, and a hike-to-ride switch that disengages the upper shell and allows for easier forward motion.

Cheap vs. Expensive

The difference between a cheap boot and an expensive boot is in the features, the construction, and the materials. A cheaper boot recreational-oriented, developed for beginner and developing skiers, and utilizes flimsier plastics to sacrifice durability for comfort. A more expensive boot has walk-to-ride functions, heat moldable liners, and rubber soles. When purchasing a ski boot through Sierra Trading Post, choose your boot based on precise measurements and functionality rather than extraneous factors such as brand name or color. Choose the boot that correctly matches size, ability, function, and desired comfort. The right boot will have you carving and shredding harder than ever before.



**Mike Restivo is a regular contributor to the Sierra Social Hub as part of #TeamSierra. Learn more about skiing, climbing and adventuring on his site: Mike Off The Map.
posted by
Michael Restivo
Blogger at Mike Off the Map
Michael is a climber and writer from Seattle, Washington. He has traveled extensively worldwide, working in Italy and Nepal. When he's not out climbing, looking for snow, or planning his next trip, Michael works in a ski shop and shares his adventures through his blog, Mike Off The Map. Team Sierra bloggers receive promotional consideration from Sierra Trading Post.
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