The calculator

Type your foot length in centimeters. If you have only measured your shoe size, use the mondopoint chart further down. The measurement is more reliable than any shoe-size conversion. Ski boots are the one item where a tape measure beats a sneaker size every time.

Measure heel to longest toe, standing, with weight on the foot.
Foot width
Measured across the ball of the foot. If you are not sure, pick medium.
Skill level
Controls how snug we suggest you go.
Days per season
Boot liners pack out; we adjust for how much you ski.

Enter a foot length above to see your sizes.

Mondo (cm)Foot length (cm)US MenUS WomenUKEU
22.022.045334.5
22.522.54.55.53.535
23.023.056436
23.523.55.56.54.536.5
24.024.067537.5
24.524.56.57.55.538
25.025.078639
25.525.57.58.56.539.5
26.026.089740.5
26.526.58.59.57.541
27.027.0910842
27.527.59.510.58.542.5
28.028.01011943
28.528.510.511.59.544
29.029.011121044.5
29.529.511.512.510.545
30.030.012n/a1146
30.530.512.5n/a11.546.5
31.031.013n/a1247
31.531.513.5n/a12.547.5
32.032.014n/a1348

Source: sizing conventions across Salomon, Tecnica, Lange, Atomic, Nordica, Dalbello, Rossignol, and Head. Minor discrepancies exist brand-to-brand. Always check the spec sheet for the specific boot you are buying.

This tool gives a starting point based on industry convention. It does not replace a boot fitter. If you can access one, go. A good fitter will spot shell fit, cuff fit, and volume issues this calculator cannot see from a cm measurement.

Your size, on the shelf at:

The mondo the calculator gives you is honored by every major boot brand. Here is where to find boots in your size across the four retailers we recommend.

Outbound retailer links are provided for reference only, no commercial relationship at this time. See our editorial independence policy for the full statement.

How to measure your foot properly

longest toe back of heel
Heel to longest toe, in cm. That number is your mondopoint.
  1. Stand on a sheet of paper against a wall. Heels flat, weight on both feet.
  2. Mark the end of your longest toe (not always the big toe).
  3. Measure heel to mark in centimeters, to one decimal place.
  4. Repeat for the other foot. Use the larger measurement.
  5. For width, measure across the widest part of the ball of the foot, standing.

Measure in the afternoon. Feet swell through the day, and ski boots need to fit the foot at its largest.

Why ski boots are "a size smaller" than you expect

The honest thing nobody selling you boots wants to say out loud: your first pair will feel too small. Probably uncomfortably so. That is not a mistake. It is how ski boots are designed to fit.

What a proper fit feels like

  • Toes just brushing the front of the boot when you stand straight.
  • Toes pulling back off the front when you flex your knees forward (the stance you ski in).
  • Heel locked. No lift.
  • Snug across the ball of the foot. Not painful. Not loose.

Why the liner packs out

Every ski boot liner is overbuilt. After five to ten days on snow, the foam compresses (this is called "packing out"), and the boot gains roughly half a mondo of internal volume. If you buy boots that feel comfortable in the shop, they will feel like slippers by week two. Slippers do not ski.

Who can size up

The calculator already handles this, but the rule: beginners skiing fewer than five days a year can sometimes go half a mondo larger for comfort, especially with narrow or bony feet. Anyone skiing more than fifteen days a year, or anyone intermediate or better, should hold the line on the calculated size.

Boot picks by width

Picks verified April 2026 against manufacturer spec sheets and US retailer pages. Specs refresh per model year.

Pair these with the mondo size the calculator gave you. All major boots sell in half-mondo increments.

Shortlisted

Best all-round intermediate

Salomon S/Pro Supra BOA 110

Medium width (100mm) · Flex 110 · BOA closure

The BOA dial replaces the lower buckles and delivers more even pressure across the forefoot than traditional buckles. Our most recommended intermediate all-mountain boot for the current season.

Check price at evo
Shortlisted

Best for narrow feet

Lange RX 110 LV

Narrow width (97mm) · Flex 110 · Traditional 4-buckle

The 97mm last is genuinely narrow, not just marketed as such. The heel pocket is excellent. If your foot is narrow and you have struggled in medium-last boots, start here.

Check price at evo
Shortlisted

Best for wide feet

Tecnica Mach1 HV 120

Wide (103mm) · Flex 120 · C.A.S. shell-moldable

The Mach1 HV is the high-volume version on a true 103mm last with C.A.S. shell punching for further adjustment. It works for wider feet without feeling sloppy. Flex 120 is advanced; drop to the HV 110 if you are intermediate.

Check price at evo

Outbound links above are for reference only, no commercial relationship at this time. Picks are shortlisted on specs and third-party reviews, not personally tested. Full methodology here · Editorial independence.

FAQ

My foot measures 26.3cm. Do I round up or down?

Round up to the nearest half-mondo. 26.3 rounds to 26.5. Boots come in half sizes and going down to 26.0 will leave you with bruised toes by lunch.

What if my feet are different sizes?

Always size for the larger foot. A slightly loose fit on the smaller foot is fixable with a footbed or custom liner. A tight fit on the larger foot is not fixable without buying a different boot.

Do I need to worry about last width or just mondo?

Both. Mondo is the length. Last is the width. A 100mm last is standard; 97-98mm is narrow; 102-104mm is wide. Buying the right mondo in the wrong last will still hurt. The calculator flags this when you mark narrow or wide.

Are ski boot sizes the same as shoe sizes?

No. A US 9 street shoe does not reliably equal a 27.0 mondo. The chart above exists for context. For any actual buying decision, measure your foot.

How tight should ski boots be?

Snug all the way around with no heel lift, but not so tight that your toes touch the front when standing upright. When you flex forward into the cuff, your toes should pull back from the front of the boot. If they don't, the boot is too long or your liner needs more pack-out time.

How long does it take to break in ski boots?

Five to ten ski days for the liner to compress and conform to your foot. The boot will feel measurably looser by week two. Buy fit to feel snug in the shop because that's what "packed-out and right" feels like in a season.

How often should I replace my boots?

Liners last about 100-150 ski days. Shells last longer but the flex index softens over time. If your boots no longer feel as supportive as they used to and you are skiing more than 15 days a year, consider replacement.