aussieskier Ski Boot Online Buying Guide

At we have selected our large ski boot range to accommodate for nearly every foot shape. Ski boots are the most important part of your ski setup and can make or break your next trip to the slopes. Not only do they have to be comfortable, they also have to have the right performance and features for the type of skiing that you like to do.

Our ski boot buying guide has been developed to help take the confusion out of buying ski boots online. If you can't come in store for a boot fitting appointment, you can call or email us and have a chat with our qualified boot fitters for the best advice.


Believe it or not, there is a difference between men and women's ski boots, and it not just the fluffy liners! Women typically have lower and proportionally bigger calf muscles and ski boots are designed through the cuff and liners to accommodate for this. Men tend to have wider feet as well, so both men and women's boots are shaped appropriately for this.


Flex or Flex Index rating is a system that manufacturers use to differentiate between different models of boots. However, the actual flex of a ski boot may vary due to a number of factors such as temperature, types of plastics used, number of buckles and style of the boot. There is no industry standard to govern what ‘flex’ actual means, so the values may be considered arbitrary and should be taken as a guide.

As men are typically taller, heavier and have stronger leg muscles than women, they are therefore able to exert more leverage and force on and through a ski boot. Because of this, the men's range of ski boots will have a higher flex Index rating than female boots.

Factors that are taken into consideration to determine an appropriate flexing boot include skier ability, aggressiveness, height, weight, terrain most often skied on, and ankle dorsiflexion (flexing the foot upwards at the ankle joint).


Performance ski boots are suitable for most skiers who are skiing on and off piste.
Freeride ski boots feature a more upright stance and maybe be seen in the side country.
Alpine Touring ski boots have walk modes and feature rockered soles that don’t fit safely in regular bindings.


Ski boots are measured in a standardized system called Mondopoint which is the length of the foot in centimetres. Measuring a foot with this method allows for accurate measurements to be made down to the millimetre, and as such an appropriate size ski boot to be chosen. Another important measurement to consider is the forefoot width of a ski boot. The forefoot width is called the last and this refers to the widest part of the boot. The measured last stated on a ski boot is based on the ‘reference’ size - a 26.5 in male boots and a 25.5 in women's boots. Boots under 98mm wide are considered narrow, 99-101mm is considered standard, and 102mm and greater are considered wide.

Comparing the width to your casual shoe width may allow you to pick an appropriate ski boot last. If you usually take an A or B in casual shoes that would equate to a narrow lasted boot. If a C or D width is your normal casual shoe width a standard lasted boot will usually be appropriate whilst an E width or wider will see you in a wide ski boot last.

As ski boots increase in size so does the last width of a ski boot. The increase is usually 2mm per size. This means if the stated last of a ski boot is 100mm in a 26.5, it will be 102mm in a 27.5, 104mm in a 28.5, etc. The same rule applies for women's ski boots. Boot fitters will try to select boots with a corresponding last width to the measured width of the foot.

Some feet may have protrusions like bunions, fatty pads, accessory bones and bone spurs which can impact the way a boot will fit. In these situations, it’s recommended to see your local boot fitter. A more narrow shell than you think may be appropriate as a good, experienced boot fitter can modify the plastic ski boot shell to accommodate for different irregularities.

Sizing Adult Ski Boots and Shell Checks

There are three different ways to size the length of a ski boot. The ideal fit in a new boot is for the toes to be touching the end of the boot when seated or standing, and then for the toes to pull off the end of the boot when flexing forward into ski position. This kind of fit is usually found by following the guidelines for a performance fit below. For beginners and less experienced skiers, a comfort fit can be a better option as they tend not to flex into the boot as much and don't tolerate the pressure on their toes well. Skiers who want a race fit will know what they're after!

Every boot fitter worth their salt will perform a shell size check. This involves removing the liner and asking the skier to insert their foot into the shell and move their toes to the end of the shell to touch with light pressure. By observing the space behind the heel they can get an idea of how the boot is going to fit for length. Using dowels as a guide, if the space available is 10mm or less this classified as a race fit. A performance fit is around 15mm space at the back of the heel, and a comfort fit is greater than 20mm at the back of the heel. If your purchasing boots online it's recommended that you do a shell fit when you receive them to double check you haven't bought boots too small or too big. If you can see a 25mm gap at the back of your heel you should definitely consider going down a size!

We've created a guide to measure feet for ski boots. Although it does not replace the value in seeing a qualified boot fitter, it will help to make better decisions when selecting ski boot sizes. Once you've figured out your measurements you can use the table below to decide what size ski boot is going to be best for you.

Measured length (mm) Race Fit Performance Fit Comfort Fit
<22.5 21.5 22.5 23.5
22.6-23.5 22.5 23.5 24.5
23.6-24.5 23.5 24.5 25.5
24.6-25.5 24.5 25.5 26.5
25.6-26.5 25.5 26.5 27.5
26.6-27.5 26.5 27.5 28.5
27.6-28.5 27.5 28.5 29.5
28.6-29.5 28.5 29.5 30.5
29.6-30.5 29.5 30.5 31.5
30.6-31.5 30.5 31.5 32.5

When sizing kids ski boots make sure to take into consideration how long you want the boots to last. If you're hoping to get 2 seasons out of them it can be good idea to select a size bigger so they can grow into the boots. If your child is a competent skier, in race club etc and needs a performance fit, it is recommended to size the boots in the same way an adult boot is sized.

Leg and Foot Shape

Ski boots come in different shapes and volumes through the foot and lower leg and it is just as important to ensure a good fit through these areas as it is to make sure the length and width of the ski boot are appropriate. As a general rule of thumb, a narrow lasted ski boot generally has less volume through the lower boot and cuff, and a wide lasted ski boot will be more voluminous through the lower boot and cuff. Skiers with more developed and muscular calves should be wary of being in a boot with low cuff volume as it can place pressure on arteries down the back of the leg that supply blood to the foot, resulting in numb and cold feet. The flip side of this is a skier having too much available volume in the cuff and experiencing poor power transmission and bruising through the shin and calf.

It’s just as important to consider the fit over the instep area of the foot. The foot is very sensitive through this area so it’s important to avoid being in a boot that's too low volume as it will cause boot compression syndrome. On the flip side, boots that have too much volume through the instep area can allow the heel to lift or the foot to ‘swim’ and move around inside the ski boot.

Ski boots that have a narrow last less than 100mm are usually low volume boots, and ski boots that have a wide last greater than 102mm are usually high volume boots. Feet that are low in volume but measure wide in the last width can be harder to match into a boot off the shelf and often need the help of an experienced boot fitter to modify the shell.

Skill Level

As a general rule of thumb, a less experienced skier should look for softer flex in a ski boot as it tends to be more forgiving whilst the skier is learning the sport. Referring to the size chart above a less experienced skier may also prefer a comfort fit. As the skier progresses in skill level and explores steeper, more variable terrain, a stiffer flexing boot may be desirable as it will be more responsive and allow the skier to transfer energy much more effectively into the skis. An intermediate to advanced and expert skier will prefer a performance fit as the more snug fit around the foot will give the skier much more direct energy transmission.


The ski boot liner is the removable inner boot that adds comfort in a ski boot. They are generally made of foam, although sometimes other materials are used, and provide insulation to the foot. Over time the foam will compress which may lead to a sloppy, loose feeling inside the boot. This is commonly referred to as packing out. Some ski boot liners are partly moldable, whilst some liners are 100% moldable. It is best to ask a qualified boot fitter for the best way to mould your ski boots.

Sock Liners, Insoles and Footbeds

Nearly all ski boots will come with a stock sock liner in the bottom of the liner. The purpose of this is to absorb sweat and cover up any seams. Skiers can experience a big increase in comfort and performance by replacing the sock liner with a prefabricated insole, and the same increase again when a prefabricated insole is upgraded to a custom footbed. A custom footbed should be made by a qualified boot fitter.

Power Straps

Power straps are velcro straps that wrap around the top of the cuff and help to keep the shin in contact with the tongue of the liner. More advanced boots generally have wider power straps or are made out of elastic materials which require more energy and effort to push forward into the boot and are better suited to advanced skiers.

Flex Adjustment

Some ski boots have the ability to increase or decrease a ski boots flex, generally by 10 flex points. In some ski boots, this is as simple as rotating a dial on the spine of the boot, wherein some ski boots a rivet may have to be added or removed to alter the flex.

Cuff Alignment

Often mistakenly referred to as canting, cuff alignment is where the cuff on a ski boot can be angled towards the inside or the outside in relation to the lower part of the boot. Some ski boots don’t have this feature, whilst others will have it on one of the hinge points and more expensive options on the inside and outside of the boot. It can be a useful tool to help compensate for bow legged or knock kneed skiers.

Hike/Walk Mode

Some ski boots have a lever or switch on the back of the boot to allow the skier to swap between ski and walk mode. They work by unlocking the cuff to increase the range of motion and make it easier for a skier to walk and hike in the side country and backcountry. They are usually only seen on Freeride and Alpine Touring boots.


Ski boots may use different materials on the sole of the ski boot depending on the intended use of the boot. Performance style boots use a flat sole which can sometimes be replaced if it wears out. Alpine Touring ski boots have a rockered sole for easier walking and use softer rubbers to increase grip on snow and rocky surfaces. Ski boot sole materials can impact compatibility with bindings so ask your boot fitter for help with this.

Freeride boots like the Tecnica Cochise and Salomon QST Pro series may have interchangeable soles which swap from the Alpine Touring rockered style to a normal Alpine flat sole. 

If you need help or advice deciding what ski boot is going to work best for you, don't hesitate to book a boot fitting appointment, call or email us, and have a chat with our qualified boot fitters. 

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