Knowing how to choose ski boots will set you up for success on the hill.
We say it all the time here at the shop: you date your skis, but marry your ski boots. If someone is looking to invest in just one piece of gear, we usually recommend investing in ski boots. Even though it appears less glamorous than the funky ski graphics and cool color combos to choose from, having the right fit is important. Figuring out how what size you should be in based on your street shoe size is a good starting point, but other factors affect how your day will go in ski boots. We’re talking a ski boot’s flex, width, cuff height and shape, BOA, and style of boot. Dive into our ski boot buying guide to get some guidance on how to choose ski boots (or at least, narrow them down).
Big disclaimer: We always recommend working with a local bootfitter. Nothing beats having someone experienced evaluate your foot shape, instability, and ankle range of motion. But, if a local bootfitter is unavailable to you, or you’re looking to do some research ahead of your bootfitting appointment, we’ve got you covered.
Ski Boot Sizing
Mondo Size (length)
Ski boots are sized in mondo point sizing. This number is the length of your foot in centimeters. Modern boots are sold in whole sizes, but in half sizes. So you’ll see numbers like 24.5, 25.5, etc., but there is very rarely a 25.0. Our ski boot size chart gives you a rough idea of what your street shoe size roughly translates to in mondo sizing. That said, many boot models and brands fit a little differently. Some brands run short, others long.
In general, regardless of ability level, we recommend sizing a ski boot so when you’re standing up straight, the tips of your toes gently touch the end of the boot. When you flex into the boot, your toes and foot should pull back. Often, folks are concerned about a ski boot fitting too snugly. Conversely, our fitters find that most skiers run into trouble when there’s too much space. As you’re skiing, if your foot is bouncing around in a hard cylinder, that can cause lots of hot spots and pain points.
The less aggressive riding you’re doing, the more comfortable the fit of the boot can be. But beware: beginners are often oversized in their rentals. As you start to progress, you might find more foot movement and more issues with your fit. So keep an eye out for sensations like cramping and hot spots. It might be time to go down a size.
There is no difference between men’s and women’s sizing when it comes to mondo point sizing. But, there are some other differences that we’ll discuss below.
Last (width)
Measured in millimeters, “last” refers to the width of the boot at its widest point, which is generally across the forefoot. A narrow last is generally around 97-99mm, an average last is from 99mm-101mm, and a wide last being wider than 102mm. Gear nerd note: The “raw” measurements here are derived from the last of a 26.5 ski boot. The smaller the boot, the last will be proportionally smaller. So a “100mm” last boot in a 24.5 will actually be 98mm. All that to say, it’s not as easy as measuring your forefoot to determine what last you should be in.
Skiers might choose a narrow or wide last for two reasons. Either their foot shape is particularly wide or narrow, or personal preference. A wider boot is more comfortable and gives you more room around your forefoot, but provides less control when you roll your skis on edge. A narrower boot is often a little less comfortable, but gives you better control.
If you deviate too far from your natural foot shape, you might start to run into fit issues. For example, a narrow foot in a wide last might give you far too much room to keep your foot stable and control your skis effectively. A wide foot in a narrow last might cause some serious pinching or hot spots.
Ski Boot Flex Rating
The flex refers to how stiff the boot is. You’ll often find it listed at the end of a model name. The higher the number, the stiffer the boot. Stiffer boots deliver more support for more aggressive riding and more challenging terrain. Softer boots tend to be more forgiving and comfortable. As a skier, you need the perfect balance of soft enough to flex into, but stiff enough to provide stability. It’s important to be able to flex into the ski boot in order to control your skis. A boot that’s too stiff will prevent you from engaging the skis properly. Too soft, and you’ll find you might not get all the control you need.
Beginners will find softer boots more accessible to flex into. As you progress, you might find that you need a stiffer boot to give you more support for exploring more challenging terrain or skiing at higher speeds. For context, most rental boots clock in anywhere from 50-80, depending on whether it is a men’s or women’s boot.
Skier size also matters with flex. Heavier skiers need the support afforded by stiffer boots, while lighter skiers often get sufficient support out of softer boots. That’s why women’s ski boots are often a softer flex, since their bodies are typically smaller than men’s.
Ski Boot Types
Generally, there are three different types of ski boots. Alpine, or downhill, boots are designed just for downhill skiing at a resort. Alpine touring, or backcountry, ski boots are lighter and better equipped for uphill/backcountry travel. Lastly, freeride, or hybrid touring ski boots. These boots fit in the middle of the two, and are designed to do both styles of skiing. We’ll dive a little deeper into each one below. In general: If you only plan to ride the resort, these are the boots for you. If you plan to spend a lot of time touring but also want a powerful boot for the resort, consider a boot quiver of an AT boot and downhill boot. On the flip side, if you plan to do some touring, or there isn’t room in the budget for two boots, check out the hybrid style boots on the market.
Alpine Ski Boots
Alpine ski boots are also called downhill ski boots, because they go downhill! These boots are engineered to provide stable and smooth support as you ride at the resort. They won’t offer tech fittings, walk modes, or other features for uphill travel. These boots tend to be a little heavier and stiffer.
Backcountry/Alpine Touring Ski Boots
Alpine Touring ski boots (AT) make it easier to go backcountry skiing. The lighter the gear, the easier it is to haul up hill. The trade-off, though, is typically less performance on the descent. By shaving weight, going with lighter buckles, and an unfixed spine with the walk mode, these boots don’t power through crud or provide the same lateral power transfer as alpine boots.
Hybrid/Freeride Boots
Hybrid, or often called freeride boots these days, attempt to make the best of both worlds by being heavier and more stable than lighter AT-specific boots, but feature tech fittings for alpine touring bindings and walk modes. They won’t feel as feather-y on the uphill, but do give you better stability on the descent. Some aggressive riders will prefer this style of boots for backcountry skiing, while more backcountry-specific riders will find them cumbersome. It all depends on your goals and what you need to be most comfortable.