Getting ready for your next mountain adventure and looking for a new pair of hiking shoes to hit the trails? Sizing questions quickly arise. A shoe that is too small creates pressure points, blisters, or bruised toenails. Too large, and you risk poor support, friction, and forward slippage on descents. Precise sizing is fundamental to your comfort and performance on the trail, whether on day hikes, multi-day treks, or alpine routes.
Before clicking “add to basket”, follow this guide to nail your size on the first try.
How to choose the right shoe size?
For years, standard advice was to buy one size up from your everyday casual shoes. This rule stemmed from past practices, when mountain boots were stiff, clunky, and worn with thick woollen socks. Today's modern hiking footwear is engineered to be more flexible, lightweight, and precise. It adapts closely to the anatomy of your foot for a natural stride, even on technical terrain.
Manufacturers now offer half and even one-third sizes. This precision fit matches foot anatomy better, but it also means you should never rely solely on your standard street shoe size. Every brand uses its own sizing matrix, with noticeable differences between seemingly identical sizes.
To get it right every time, rely on an objective measurement: the exact length of your foot in centimetres. This measurement serves as your benchmark across all brands. With it, you can navigate size charts effortlessly and pick the perfect fit.
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Measuring your feet accurately
Take a few minutes to measure your feet accurately. This simple step prevents sizing errors and unnecessary returns.
Here is how to do it:
- Place a large sheet of paper on the floor against a flat wall. Tape it down securely so it does not shift.
- Stand up straight, barefoot, with your heels firmly against the wall. Distribute your weight evenly across both feet.
- Have someone mark the tip of your longest toe on the paper (usually the big toe, though sometimes the second toe extends further).
- Then, using a rigid ruler or tape measure, measure the distance from the wall to the mark in a straight line perpendicular to the wall.
Repeat the process for both feet. Keep the larger of the two measurements, as having one foot slightly longer than the other is very common. A few millimetres make a real difference out on the trail, especially on steep descents or long stages.
Record the measurement accurately without rounding up. This length in centimetres is your definitive reference for finding the right size on manufacturer charts.
Understanding sizing conversion charts
Every manufacturer provides a sizing chart matching foot length to European (EU), British (UK), or US sizes. These charts generally include built-in comfort room to accommodate standard sock thickness and keep toes from hitting the front of the shoe.
You do not need to add extra centimetres to your measurement. If your foot measures 27.3 cm, add nothing: look up this exact measurement in the brand's size chart and select the corresponding size. For Cimalp footwear, this matches an EU 44.
If your measurement falls between two sizes, choose the larger one. This accommodates volume fluctuations caused by heat, exertion, or moisture. A slightly larger boot also delivers superior comfort on descents, where feet naturally slide forward.
Here is the size chart for Cimalp footwear, factoring in foot swelling during physical activity:
| Foot length (cm) | 21,8 | 22,6 | 23,3 | 24 | 24,6 | 25,3 | 26 | 26,6 | 27,3 | 28 | 28,7 | 29,3 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| EU Shoe Size | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 |
| UK Shoe Size | 3,5 | 4 | 5 | 6 | 6,5 | 7 | 8 | 9 | 9,5 | 10,5 | 11 | 12 |
| Men's US Shoe Size | 4 | 5 | 5,5 | 6,5 | 7 | 8 | 8,5 | 9 | 10 | 11 | 12 | 13 |
| Women's US Shoe Size | 5 | 6 | 6,5 | 7,5 | 8 | 9 | 9,5 | 10 | 11 | 12 | 13 | 14 |
Specific cases to keep in mind
Several factors can influence your shoe size choice:
- Type of hike: On multi-day treks with a heavy backpack, feet swell more significantly. You should therefore choose boots with slightly greater internal volume. For day hikes or fitness walks, a closer fit can provide extra precision.
- Sock thickness: Thick or technical socks take up extra space in the boot. Always measure and try on shoes with the exact socks you plan to use on the trail.
- Footwear type: A low-cut shoe for fast hiking does not offer the same support or meet the same demands as a high-cut mountaineering boot. The stiffer the footwear, the more precise the fit must be.
- Foot shape: Some hikers have high insteps, wide feet, or claw toes. In these cases, choose a brand or model designed specifically for these traits. Many brands offer dedicated “wide” or “high volume” fits.
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How to properly fit your hiking boots
Once your pair arrives, take the time to test it properly. The goal is to simulate real trail conditions as closely as possible.
Follow these simple steps:
- Put on your usual hiking socks—the exact pair you intend to wear on the trail.
- Try boots on at the end of the day, when feet are naturally slightly swollen.
- Lace up your boots properly, matching the exact tension you would use on a hiking trail.
- Walk around for several minutes, go up and down stairs, and do a few squats. Check that your foot does not slide forward and your heel remains firmly locked in place.
A good hiking boot must provide firm hold without pinching. Your toes should be free to wiggle. You should feel no pressure points and no heel slip. Take the time to re-lace your boots after a few minutes: this lets your foot settle in and fine-tunes the fit.
If you notice discomfort early on or feel your foot slipping inside the shoe, do not hesitate to request a different size. It is much better to exchange now than suffer out on the trail.
