How to Size Ski Boots
Buying ski boots can be an experience fraught with uncertainty. As you wring your hands inside of your local ski shop and ponder whether or not to drop around $700 on the boots on your feet, take some solace in the fact that you read this article first.
First thing: Measure Your Foot
Alpine and Telemark ski boots work on a unique sizing scale called Mondopoint (MP). The scale is very simple, and is essentially the length of the foot in centimeters.
- Make sure to measure both feet, since most people have feet that are slightly different lengths. Ideally we try and size to the smallest of the two feet. Most new boots these days have some type of thermo-formable liner, so it will be pretty easy to create some space in the liner.
- One other important step in foot measurement is taking a measurement of your foot both un-weighted (sitting) and weighted (standing). This will help determine how much your arch collapses when bearing load. Many people experience some arch collapse that effectively lengthens the foot ¼ to ½ cm. But some folks can experience up to 1cm of foot elongation, which will greatly affect boot fit and performance.
- If you do have any significant arch collapse that results in a weighted foot measurement that is at least ½ cm longer than the un-weighted measurement, you should highly consider an aftermarket insole to help keep your foot at its natural, un-weighted length. It will then be easier to get the most appropriate sized ski boot that will be both comfortable and high performance.
And then: Do a Shell Fit
Once you have your ski boots, the most effective way to gauge if they are the correct size is to do a shell fit.
- Remove the liners from the boot shells, then place both feet in the shells.
- Slide the feet to the front of the shells, so that the toes are flat and touching the front of the shell. Now you should have some space between your heels and the back of the shell.
- Bend at the knees (but keep your heels down) to check about how much space you have. An index finger’s width equals a little more than ¼ inch, and is what we use to determine a good performance oriented fit.
- If you stack the index and middle finger you get about ¾ inch width. This amount of space behind the heel will be a more comfort oriented fit and may be better for folks who have poor circulation and easily get very cold feet. This fit may also be a bit more appropriate if your boot does not have a thermo-formable liner.
Bonus: Don't Forget About the Liner
Now that you have determined that you have an appropriately sized shell, you can fit the boots for the width and volume of the foot. You can also determine if you need to thermo-fit the liners, and where to focus on creating some space.
- Place the liners back in the boot shells. If you have an aftermarket insole, make sure that is in place as well. Another good idea would be to wear the socks you intend to wear while skiing. A thick heavy sock can have a big impact on how the boot fits.
- Put the boots on your feet, and make sure to buckle them down to the tightness you would feel comfortable skiing them.
- Stand up. Without putting much weight against the front of the shell (on the shins), figure out where your toes are in the liner.
- Ideally, in a boot with a thermo-formable liner, the toes will be flat and touching the front of the liner. If there is space between the toes and the front of the liner, the boot may be too big. If the toes are crunched up and squeezed by length or width, the boot may be too small.
- Take a moment to hang out in the boot, remember you are going to be skiing in these all day. What feels comfortable for a couple of minutes may not feel comfortable for several hours. So take a walk around, sit down for a bit, get back up and walk around some more, just hang out in them for a while to make sure they are as comfortable as you desire. See if any pain, discomfort, or numbness develops. Or, if you had some initial discomfort, see if it dissipates.
- Check the buckles on the lower part of the shell. Do you need to bottom the buckle ladder out for it to feel snug? If so, the boot may have too high a volume and you should consider a lower volume option or go to a boot fitter who can appropriately shim the boot to decrease the effective volume.