How to Choose Ski Boots: Size, Width, Flex and Soles
A five-step way to choose ski boots: size, width, flex, soles and closures, with what more than 1,800 boot models tell us about each.
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Ask experienced skiers what to spend money on first and most will say boots. Skis only do what your boots tell them, and a boot that hurts will end your day whatever is on your feet. The good news is that boots are easier to narrow down than they look: size, width, stiffness and sole type rule out most of the 1,865 boot models in our catalog before you've looked at a single color.
1. Get the size right
Ski boots are sized in mondopoint, the length of your foot in centimeters (a 27.5 fits a 27.5 cm foot). Measure both feet standing, use the longer one, and don't size up for comfort: a boot that's too long lets your foot slide, which causes more pain than it solves. Our ski boot size chart has the conversions from US and EU shoe sizes.
2. Match the width to your foot
The "last" is the width of the boot's shell at the forefoot, measured on a mid-range reference size, often 26.5. Here is how the adult boots in our catalog with a listed last spread out, and how stiff they typically are:
| Last width | Models | Typical flex |
| 97 mm or narrower | 94 | 120 |
| 98–99 mm | 206 | 110 |
| 100–101 mm | 334 | 110 |
| 102–103 mm | 209 | 95 |
| 104 mm or wider | 40 | 100 |
Most boots sit at 100–101 mm, which suits an average foot. Narrow lasts are mostly stiff performance boots: the typical one has a 120 flex. Wide lasts lean softer and more comfort-minded, at a typical 95 to 100. So if you have narrow feet and want a soft boot, or wide feet and want a very stiff one, expect a shorter list to choose from. Many shells can be stretched or heat-molded a few millimeters, but it's easier to start close.
3. Choose a flex for your weight and ability
Flex is how hard the boot is to bend forward. Higher numbers are stiffer. Makers don't measure it the same way, so a 100 from one brand can feel like a 110 from another, but the number is still a good guide. Here's how the catalog spreads out, with typical list prices:
| Flex rating | Men's models | Women's models | Unisex models |
| 70 or softer | 2 | 28 ($357) | 4 ($549) |
| 75–90 | 64 ($450) | 184 ($530) | 47 ($475) |
| 95–110 | 174 ($650) | 242 ($750) | 125 ($700) |
| 115–120 | 128 ($800) | 73 ($850) | 70 ($870) |
| 125 and stiffer | 99 ($900) | 11 ($950) | 114 ($950) |
Women's boots cluster between 75 and 110, men's between 95 and 120. Each step up in stiffness adds roughly $100 to $200 to the typical list price, partly because stiffer boots tend to come with better liners and more adjustment.
As a rough guide, newer skiers do best in a softer boot (around 70–90 for women and 80–100 for men), confident intermediates a step up, and strong, aggressive skiers 120 and above. Heavier or taller skiers can go stiffer than their level suggests, lighter skiers softer. Our guide to ski boot flex explains the trade-offs, and women's ski boots covers how women's models differ.
4. Check the sole and your bindings
The sole decides which bindings a boot can go in. Of the roughly 1,000 boots in our catalog with a listed sole type:
- 781 have GripWalk soles, the rockered, rubber-treaded sole that makes walking easier. They need a binding that accepts GripWalk, which most current alpine bindings do.
- 119 have standard alpine soles, the flat sole that fits every alpine binding. Most race and many high-end boots use it.
- 71 are touring boots, usually with tech inserts for pin bindings and a walk-friendly sole.
- A handful are telemark boots (NTN or 75 mm), which need telemark bindings.
If you already own bindings, check what they accept before you buy boots. Our guides to ski bindings and alpine vs touring vs hybrid bindings go through compatibility.
5. Decide on closures and extras
Most boots still close with buckles, but dials have caught on fast. Five of the six current boots stocked by the most US shops on 31 October 2026 used a BOA dial: the K2 BFC 100 BOA (41 shops), Nordica Speedmachine 3 110 BOA (35), Atomic Nexus 95 BOA W (33), K2 BFC 95 BOA (32) and Nordica Sportmachine 3 100 BOA (31). The sixth was the Armada AR One 110 MV (29). We look at what a dial does and doesn't change in BOA ski boots, and compare two popular dial boots in K2 BFC 100 BOA vs Nordica Sportmachine 3 100 BOA.
Other features worth a look: a walk mode if you hike to the lift or tour, heat-moldable liners and shells if your feet are hard to fit, and an adjustable cuff if you have wide calves.
What boots cost this season
On 31 October 2026, the typical lowest in-stock price for a current ski boot at US shops was $600. Last season's boots were typically $400, and four in five were at least 20% under list. If last season's version of a boot fits you, it's often a very good buy; when do ski prices drop? has the details.
Whatever you choose, fit beats features. Narrow the list by size, width and flex, then compare prices on our ski boots page.