23 cm of foot length: what size is it and how to get it right when buying

With 23 cm feet, the most common reference in Europe is around a 36, although in some manufacturers and models it may come closer to a 37. The figure is not automatic: it depends on the sizing system, the last, and the amount of room each brand leaves at the toe.

In sports footwear, where the foot needs space to expand when running or walking long distances, that same length may require a slightly more generous size. The difference seems minimal on paper, but in practice a few millimeters completely change the feeling of fit, stability, and the risk of chafing.

The 23 cm measurement and the size that appears most often

The most repeated equivalent for a 23 cm foot is a European size 36. That correspondence appears frequently in general conversion charts and manufacturer guides, but it should not be read as a fixed rule. The same foot length can translate into different numbers depending on whether the shoe has a narrow toe box, is designed for women, men, or children, or if the brand runs slightly small.

In some charts, 23 cm also borders a 36.5 or even a 37. That variation is due to the fact that not all sizing systems use the same internal base. The visible size on the box does not always reflect the real usable space, which is what truly matters to the foot when it lands on the sole and pushes forward with each step.

That is why, rather than looking for a single number, it is better to interpret the measurement as a range. 23 cm usually corresponds to a 36, but the correct choice may go up or down half a size if the model is narrow, if thick socks will be worn, or if more freedom is desired in impact sports like running.

How to measure your foot properly before checking the chart

A reliable measurement starts at the end of the day, when the foot has already supported hours of load and shows its most realistic size. All you need is a sheet of paper on the floor, a pencil, and a ruler. The heel should be against the wall, weight distributed naturally, and the longest toe marked precisely. That final detail is decisive: the longest toe is not always the big toe.

Once you have the length, repeat the process with the other foot. It is normal for one foot to be larger than the other, even by a few millimeters. In footwear, the useful reference is usually always the larger foot, because a shoe that is too short hurts more than one with a small amount of extra room.

It also helps to measure with the type of sock that will be worn. In running shoes, a thin technical sock does not take up the same space as a thick cotton sock. That detail, which may seem minor, changes the feeling of fit at the toe box and can justify moving from a snug 36 to a 36.5 or 37 in very close-fitting models.

Why 23 cm does not mean the same thing across all brands

Brands do not manufacture on identical molds. Two shoes that show the same size can have different interiors because of the shape of the toe box, the thickness of the insole, the curvature of the instep, or the width of the forefoot. That is why a person may wear a 36 in one brand and need a 37 in another without their feet having changed.

The last is the heart of the matter. It is the structure on which the shoe is built, and it determines whether the model hugs the foot with a narrow profile or leaves a more open feel. A 23 cm foot in a narrow last may feel better in size 37, while in a more generous last the 36 may fit perfectly.

The shoe’s purpose also matters. A dress loafer does not behave the same way as a training shoe. In the former, the fit is usually more exact; in the latter, the foot needs room to expand during effort and, in some cases, a little extra space in front to prevent the toes from hitting on downhills or during the push-off phase.

How much room should you really leave?

In everyday footwear, a margin of between 0.5 and 1 cm is generally considered reasonable in the forefoot area, as long as the foot does not slide around inside the shoe. That space is not a luxury: it allows you to walk naturally, avoids pressure on the toes, and leaves room for the foot to expand throughout the day.

In running shoes, the practical recommendation usually leans toward the upper end of that range, especially on long runs or downhill sections. The foot moves slightly forward with each stride, and if the toe box is too short, the toenails pay the price. Half a size up can make the difference between a comfortable outing and a session with discomfort.

That said, more space does not always mean better. A shoe that is excessively large causes friction, instability, and less precise foot strike. The foot begins compensating with the toes, as if trying to grip the ground, and that tension ends up loading the calves, the sole, and the instep. The correct fit is a delicate balance between freedom and support.

What changes between women’s, men’s, and children’s sizing

The same 23 cm length does not translate the same way in all segments. In many European systems, a foot of that measurement fits quite naturally into women’s footwear around a 36. In men’s footwear, the number may feel smaller within the overall scale, because men’s sizes start higher and the lasts are usually wider.

In children’s footwear, 23 cm already places the foot in an advanced stage of growth, close to teenage or even small adult sizes, depending on the brand. Here, the margin of purchase becomes more important, because children’s feet grow quickly and because a shoe that is too tight can interfere with the comfortable development of the toes and support.

It is also worth distinguishing between age and length. Size is not decided by years, but by real centimeters. Two children of the same age can have very different sizes, and two adults of the same height can wear different numbers. The foot’s centimeters are more honest than any calendar-based estimate.

Common mistakes that lead to the wrong purchase

One of the most frequent mistakes is blindly trusting the size you always wear. That habit works only halfway, because each brand reinterprets sizing. Another classic mistake is focusing on the number without looking at foot width. A 23 cm foot can be narrow, medium, or wide, and that variation changes the final result as much as the length.

Buying also goes wrong when the foot is measured at rest and natural expansion is not considered. Late in the afternoon, after walking or standing, the foot increases in volume. That explains why a shoe that seemed correct in the morning may feel tighter at the end of the day. The most useful measurement is the realistic one, not the idealized one.

Another mistake is forgetting the intended use. A pair for city walking does not require the same tolerance as running shoes or winter boots with thick socks. In each case, internal space changes in value and the number on the label tells only part of the story.

How to read size charts without getting lost

Conversion charts are useful, but they work like compasses, not GPS. They point in a likely direction and help you avoid starting from scratch, although they do not replace the specific model. For a 23 cm foot, most European charts point to a 36, but some make the jump to 36.5 or 37 depending on the manufacturer.

In international conversions, the picture becomes more complex. The US and UK systems use different scales, and the same foot can fall into numbers that seem unrelated to one another. That is why looking only at the size written on the tongue can lead to mistakes when buying online, especially when the purchase crosses borders.

The key is to read the manufacturer’s own chart and, if available, the internal length in centimeters. When a brand publishes the shoe’s usable space, the comparison becomes more precise. In practical terms, you are not comparing one label with another, but foot against the shoe’s real interior, which is the relationship that matters.

The special case of running and sports shoes

In running, a 23 cm foot should rarely feel cramped at the toe box. During the run, the foot expands, absorbs impact, and moves forward inside the shoe with each landing. A shoe that is too tight can cause black toenails, pressure on the metatarsals, and loss of comfort in the later stages of training.

That is why, in sports footwear, people usually talk about leaving a small cushion in front of the longest toe. That extra space is not a trend, but a consequence of movement mechanics. The foot runs, swells, and shifts, and the shoe should anticipate that behavior rather than fight it.

In addition, not all running models fit the same. Some are narrower in the midfoot, others have wider toe boxes, and others reduce space to create a feeling of precision. A 23 cm foot may fit comfortably in a 36 for walking, but in a racing shoe it may require a different size to preserve the working room that running requires.

What to do when the number seems right but isn’t

There are times when the size matches on paper and yet something feels off. The heel lifts, the toes hit the front, the instep presses, or the side rubs. In those cases, the problem is usually not the length, but the model’s shape. The correct size may hide a design that is unsuitable for that particular foot.

When that happens, it is worth looking at the width, the type of closure, and the flexibility of the instep. A well-adjusted lace can solve more than a simple size up, and a thin insole can free up valuable millimeters without changing the visible number. Sometimes the solution is in the model, not the figure.

If the shoe has already been bought, the home test should be done calmly, on a clean surface, without removing tags right away. Walking around the house for a few minutes is enough to tell whether the toe box is too short or whether the foot slides too much. Early comfort usually predicts real comfort; a shoe that hurts from the very beginning rarely improves with use.

Children’s sizing and the foot’s rapid growth

In children and teenagers, a 23 cm foot can change size in a matter of months. Growth is not linear and often happens in sudden jumps that surprise families. For that reason, regularly checking the foot matters more than any approximate calculation based on age or school stage.

The mistake of buying too large so it lasts longer is as common as it is ill-advised. Too much room makes the foot lose support, move inside the shoe, and work in a disorganized way. During growth, that leads to trips, blisters, and a feeling of instability that should not be normalized.

The sensible approach is to look for a balance between room and fit. A child’s foot needs space to move, but also a clear structure to hold it in place. At that stage, 23 cm is no longer a small foot; it is a foot that deserves the same measurement precision as any other, because every millimeter counts for comfort and development.

What to remember before completing the purchase

A 23 cm foot usually corresponds to a European 36, although the jump to 36.5 or 37 is not unusual depending on the brand, the last, and the intended use. That is the central idea that prevents most mistakes: the number guides you, but does not decide on its own.

The exact foot measurement, taken calmly and compared with each manufacturer’s chart, gives better results than any inherited habit. When footwear is chosen well, you barely notice it; it accompanies your stride like a good piece of machinery, without noise, without pressure, without reminding you of its presence at every step.

In a successful purchase, the size stops being a puzzle and becomes a concrete, almost everyday measurement. The foot fits, breathes, and moves forward. And that small margin between doubt and certainty is, in the end, what separates any old number from a truly useful shoe.

Medical reference: Measuring your feet, NHS.