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Description: Convert Shoe Sizes

Convert shoe size

In this article you will learn how to calculate the shoe size based on the foot length and how the different standards can be converted into each other.

The correct shoe size is important

It is not always easy to find the correct shoes. On the one hand, they should be visually appealing and on the other hand, they must also fit well. If the shoes are too big, then you don't have a firm grip and you might slide your foot back and forth and if the shoes are too small, walking might be very uncomfortable and you might easily get pressure points or blisters.

To unify the size indication of shoes, certain standards have been developed. The most common of these are the European (EU), American (US) and British (UK) standards. The following chapters explain the differences between the various shoe size standards and how they can be calculated based on the length of the foot.

Correct measurement of the foot length

The length of the foot is decisive for the shoe size. To determine the optimal shoe size, the length of the foot must first be measured. The best way to do this is to proceed as follows:

  1. Place the foot on a sheet of paper and mark the circumference. The trick is to hold the pencil so that the lead hits the sheet of paper as vertically as possible under the edge of the foot.
  2. Measure the longest distance with a ruler.
  3. Calculate the shoe size based on the foot length using our converter.

Measure foot length correctly for shoe size

The best time to measure foot length is in the afternoon or evening, as feet tend to get bigger during the day. It is also best to measure both feet and then use the larger foot to determine the shoe size.

Calculation of shoe sizes based on foot length

This section shows how the most common shoe size standards can be calculated based on foot length.

European (EU) Standard

The German, French, Spanish and Italian shoe sizes comply with the EU standard. There is a simple formula for the calculation:

Unit: centimeters $$ \begin{equation*} \begin{split} \text{EU size}&=1,5\cdot(\text{Foot length})+2\\ \text{Foot length}&=\frac{(\text{EU size})-2}{1,5} \end{split} \end{equation*} $$

Unit: inch $$ \begin{equation*} \begin{split} \text{EU size}&=3,81\cdot(\text{Foot length})+2\\ \text{Foot length}&=\frac{(\text{EU size})-2}{3,81} \end{split} \end{equation*} $$

American (US) Standard

The US standard distinguishes between men, women and children for shoe sizes:


Unit: centimeters $$ \begin{equation*} \begin{split} \text{US size}&=1,181\cdot(\text{Foot length})-22\\ \text{Foot length}&=\frac{(\text{US size})+22}{1,181} \end{split} \end{equation*} $$

Unit: inch $$ \begin{equation*} \begin{split} \text{US size}&=3\cdot(\text{Foot length})-22\\ \text{Foot length}&=\frac{(\text{US size})+22}{3} \end{split} \end{equation*} $$


Unit: centimeters $$ \begin{equation*} \begin{split} \text{US size}&=1,181\cdot(\text{Foot length})-21\\ \text{Foot length}&=\frac{(\text{US size})+21}{1,181} \end{split} \end{equation*} $$

Unit: inch $$ \begin{equation*} \begin{split} \text{US size}&=3\cdot(\text{Foot length})-21\\ \text{Foot length}&=\frac{(\text{US size})+21}{3} \end{split} \end{equation*} $$


Unit: centimeters $$ \begin{equation*} \begin{split} \text{US size}&=1,181\cdot(\text{Foot length})-9,75\\ \text{Foot length}&=\frac{(\text{US size})+9,75}{1,181} \end{split} \end{equation*} $$

Unit: inch $$ \begin{equation*} \begin{split} \text{US size}&=3\cdot(\text{Foot length})-9,75\\ \text{Foot length}&=\frac{(\text{US size})+9,75}{3} \end{split} \end{equation*} $$

British (UK) Standard

In contrast to the US standard, the UK standard only distinguishes between adults and children:


Unit: centimeters $$ \begin{equation*} \begin{split} \text{UK size}&=1,181\cdot(\text{Foot length})-23\\ \text{Foot length}&=\frac{(\text{UK size})+23}{1,181} \end{split} \end{equation*} $$

Unit: inch $$ \begin{equation*} \begin{split} \text{UK size}&=3\cdot(\text{Foot length})-23\\ \text{Foot length}&=\frac{(\text{UK size})+23}{3} \end{split} \end{equation*} $$


Unit: centimeters $$ \begin{equation*} \begin{split} \text{UK size}&=1,181\cdot(\text{Foot length})-10\\ \text{Foot length}&=\frac{(\text{UK size})+10}{1,181} \end{split} \end{equation*} $$

Unit: inch $$ \begin{equation*} \begin{split} \text{UK size}&=3\cdot(\text{Foot length})-10\\ \text{Foot length}&=\frac{(\text{UK size})+10}{3} \end{split} \end{equation*} $$


In this article we learned how to measure the foot length correctly and how to calculate the shoe size in the desired standard. The easiest way to get the correct shoe size is to use the shoe size converter provided here for free. This also has the advantage that you not only get the concretely calculated shoe size value, but in principle all potentially possible shoe sizes are displayed. The data for this comes from an analysis of various shoe size tables. Of course, there is no 100% guarantee that the shoe really fits, because the manufacturer does not necessarily have to adhere to the respective standard, but can also deviate from it.

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Posted on 02.12.2020 | Last modified on 08.01.2021