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Birkenstock Size Conversion – An Expert Guide

Navigating the Birkenstock size conversion can be a common challenge with buying Birkenstocks online. Designed and manufactured in Europe, the original size (before conversion) is always EU Continental sizes and these do not translate directly to UK or US sizes – they are just different.

Unfortunately, the various size translations and width options are often incorrectly published online, which means buying your first pair of Birkenstock sandals online can be a daunting task. Read on, for our expert advice on how to get sizing right for you.

Begg Shoes are one of Scotland’s longest-standing independent shoe retailers having been established in 1866. Six generations of the Begg family later, the business now boasts a team of footwear experts.

Birkenstock Size Conversion Chart

Birkenstock Size Conversion Chart EU UK US

Begg Shoes Size Conversion Table

EU Size UK Size US Size Shop By Size
35 2.5 4.5
36 3 5 Shop Size 3
37 4 6 Shop Size 4
38 5 7 Shop Size 5
39 5.5 – 6 7.5 Shop Size 6
40 6.5 8.5
41 7 9 Shop Size 7
42 8 10 Shop Size 8
43 9 11


Birkenstock Size Conversion Chart – According to their website

It may be very confusing when purchasing Birkenstocks as their conversion does not match the conversion chart that we use from the Society of Shoe Fitters.

35 2.5 4 – 4.5
36 3.5 5 – 5.5
37 4.5 6 – 6.5
38 5 7 – 7.5
39 5.5 8 – 8.5
40 7 9 – 9.5
41 7.5 10 – 10.5
42 8 11 – 11.5
43 9 12 – 12.5


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Do Birkenstocks Run True To Size?

The short answer is no. For various reasons, Birkenstock size conversion can be difficult to get right on the first time and we have found that Birkenstock fit big.

The main reason for this is size conversion between UK, EU & US which can be very misleading. We advise purchasing the shoes in the manufactured EU Continental size. That way you reduce the risk of ordering the incorrect size when relying on retailer size conversion, which is always just a guide and not a guarantee. If you know you take an EU 39 then that’s what you should look for – rather than switch to UK or US equivalents and take a risk.

We find that different online stores will convert their sizes differently. Our blog on EU to UK shoe size explains why this is such a common problem.

Birkenstock Narrow Fit vs. Regular Fit

Birkenstock offers two different width fittings – Narrow Fit and Regular Fit (closer to wide fit). While this may seem fairly straightforward, the naming of these fittings is actually a very common source of problems for online shoppers. Here is our advice based on years of experience selling the brand in our stores. Take care to pick the width fitting that is best for you to avoid aching feet.

Narrow Fit: We find that most customers opt for the Narrow option (around 80% of women) and typically we consider this to be more of a Standard Fit. This causes a lot of confusion as you might expect – the name is misleading.

Regular Fit: This width fitting is best suited to a wider foot or those who prefer a little more room on the footbed. Regular Fit is the more popular fitting for Men, but it is well worth noting that many of the iconic Birkenstock styles are unisex including Arizona.

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Birkenstock Soft Footbed vs. Original Footbed

Birkenstock has brought out a new range of iconic styles with a Soft Footbed. But what is the difference between the soft footbed and the original footbed?

The Original Footbed features four layers, as detailed below.

Birkenstock Original Footbed Cross Section

  1. First Layer of Jute. This forms the foundation of Birkenstock footbeds and helps to ground the natural cork and latex layer.
  2. Cork and Latex Footbed. This is what gives the iconic footbed its anatomical shape. Highly flexible and shock absorbent, the cork and latex core offer support and relief. The natural materials of the cork offer insulation against hot and cold temperatures, and are absorbent too, to help keep feet cool and comfortable.
  3. Second Layer of Jute. This is placed on top of the Cork and Latex core, offering increased flexibility and durability.
  4. Suede Lining. The natural suede leather absorbs excess moisture to keep your feet pleasantly cool.

The Soft Footbed features the same four layers as above, with an additional fifth layer of foam under the suede lining and above the second layer of jute.

5. Foam Insert. The Soft Footbed Birkenstock models have an additional fifth layer of anatomically shaped foam. This layer features millions of tiny air bubbles, offering a softer and more comfortable experience underfoot.

How Do Birkenstocks Fit?

The iconic footbed used in the Birkenstock range is relatively hard and unforgiving compared to other brands. While a bit firm, the standard footbed also has very distinctive features that help to support and hold your foot. 

The deep heel-cup will support your feet almost as if it were in a closed shoe. While the arch support offers you stability with every step. The toe grip is one of the most recognisable features of Birkenstock sandals. This supports the natural position and rolling motion of the toes to keep them loose and spread out.

This means that if you get the right size – Birkenstocks can be incredibly comfortable and supportive. In the event you pick one that is too big or too small, however, you could really regret it.

Are Birkenstocks Worth It?

When it comes to Birkenstocks, the answer to whether they’re worth it is a resounding yes. These German-made sandals offer comfort and support, thanks to their unique contoured footbed that conforms to the shape of your feet over time. Not only are they built to last with high-quality materials, but they also come in a range of styles and colours to suit any taste. Whether you’re running errands, exploring a new city, or just lounging at home, Birkenstocks are a reliable choice that you won’t regret investing in.

Birkenstock Size Conversion Guide - Shop Our Range with Free UK Delivery on orders over £30

How To Check Your Birkenstocks Fit Correctly

Stand up with the sandals on, straps fully open if these are adjustable, then feel your feet will naturally spread under your body weight. Your foot should feel supported, but be able to move freely. Your heel and toes should not overlap or rub up against the firm outer ridge of the footbed.

Make sure your toes do not rub up against the edge at the front of the sandal – this can rub and cause corns or blistering over time. Don’t be afraid to go up a size and try it on, if you are concerned, or consider switching to a Regular Fit alternative if you need more width.

Once you are happy with the fit of the footbed you can now go ahead and fasten the straps. The straps should hold your foot in the correct place on the footbed, stopping you from sliding forward or back during regular walking. Straps should hug your foot without being too tight – remember your feet will expand on hot days for example.

Take a few steps to see if the straps hold your foot securely and adjust them once more if you feel that they are too tight or loose. You should not feel the buckles digging in at all, this might indicate you need to loosen the strap or that the shape and style may not be right for you.

Birkenstock Size Conversion Guide - Shop Our Range with Free UK Delivery on orders over £30

Breaking In Birkenstock Sandals

The last step to getting your Birkenstocks to fit properly is to “break them in”. More important before breaking in your brand new Birkenstocks is to ensure the footbed length is correct. No amount of wear will increase the overall length and it would be best to return them (before wearing them outdoors) for an exchange or a refund before fully committing to wearing them in.

For best results, we recommend that you wear your sandals for a few hours to get used to the footbed. Start with short indoor wear, then work up to longer walks and regular wear. We recommend you don’t set off on a long walk or holiday without doing some of the softening off first – take it slow! The footbed will soften and mould to your foot, though this can be a slow process. Loyal Birkenstock fans will tell you it’s worth it and that a fully bedded in Birkenstock is unbeatable for comfort.

The straps will stretch a little with wear, though Birko Flor styles will only stretch a little. We recommend the leather styles for a truly personalised fit, superior comfort and breathability. These are usually a little more expensive but worth the extra money for the added comfort and personalisation.

What is Birko-flor?

Unless specified as leather most of our Birkenstock styles are made using Birko-Flor® which is a premium synthetic material. It is an easy-care, skin-friendly and tear-resistant material and although it looks and feels very similar to leather, but will not behave in the same way as leather in terms of stretch and breathability. This is a fantastic material that has proven to offer a durable look and feel, in a huge range of metallic, glitter and other premium fashion materials, which are very difficult and expensive to replicate on leather. Overall, this is a great value premium material and not to be feared, if you would usually look for leather uppers.

If you prefer the classic matt leather finishes and a slightly more rugged and worn look in your sandals, we always recommend spending a little more and buying genuine leather. These also offer superior stretch and breathability, if you are going to spend a lot of time wearing your sandals.


Birkenstock Size Conversion Guide - Shop Our Range with Free UK Delivery on orders over £30

Why Choose Birkenstocks?

We get asked this question a lot as some may think that they’re pretty pricey for a “basic” sandal, but there’s so much more to them than one might think and it all comes down to the unique design of their footbed and high-quality construction. If you love the style of the iconic Birkenstock, then we recommend you buy the real thing and you’ll love them for longer than a lookalike.

Browsing through the internet nowadays you’ll find a plethora of Birkenstock copies and knock-offs, especially of the two-strap classic Arizona. Like any footwear fashion icon, many other brands have created their own versions but in this case, the original is very hard to beat. Lookalike styles are often made using cheaper and inferior materials and construction and while this might be good enough for occasional wear, we always advise that better quality materials and design usually lead to a shoe looking and feeling better for longer.

While Birkenstock has spent many years, dedicated to the perfection of their signature styles and orthotic-inspired footbed, the cheaper copies available are made by manufacturers who spend very little time or effort refining their products. Often, this will be evident once you start wearing a cheaper version, either due to poor fitting qualities or perhaps just the materials don’t look as good as the original Birkenstock would. To take a closer look at our most popular Birkenstock styles take a look at our Top 10 Birkenstocks.


Birkenstock Size Conversion Guide - Shop Our Range with Free UK Delivery on orders over £30

Alternatives to Birkenstock

If you are looking for a more affordable comfort sandal check out our Women’s Slide Sandals collection where we have a wide range of options from top brands and shoemakers.

If comfort is your top priority then take a look at our Flat Sandals and Comfortable Sandals from brands like Heavenly Feet, Remonte and Gabor.


Within our Birkenstock size conversion guide, we hope we have helped you find the best size and width. The brand is synonymous with iconic styles such as the Arizona sandal and Boston Clog, both crafted in Europe using premium materials. A uniquely contoured footbed shape is one of their distinguishing features, widely copied in the footwear industry, but also the cause of serious discomfort if you don’t get the right size and fitting for you.