US to UK shoe size ratios are not always apparent when shopping online. But it is important to know what you are selecting before you end up with a purchase that you have to return for the mistake of sizing. Especially when that return involves exportation and after having already paid import duties.
Generally speaking, there are two sets of rules when it comes to US to UK shoe sizes: 1. Your US shoe size will be one entire size larger than your UK shoe size i.e. UK8 = US9, and 2. Your US shoe size will be half a size larger than your UK shoe size i.e. UK8 = US8.5. So how do you know which of those to go off of when ordering UK-size shoes yet being in the US?
While not a hard fact, I have found in my extensive handling of all shoes, and having lived in London for 7 years, that most shoes fall into rule one, where the UK to US shoe size ratio is one entire size difference. The anomalies are generally found in the upper caliber shoemakers where lasts are more contoured and thus hugging. For example, Gaziano & Girling where I have found that my US7.5 shoe size translates to being a UK7 in their shoes. This is also the same in many of Edward Green’s lasts, where they actually state this on their footwear. The only pair I ever had was a Galway boot. On the inside, it stated the shoe size 7/7.5. That was a ‘UK7/US7.5.’
To make it even more confusing you then have different lasts that might break their own rules. For example, the Edward Green boot that I had was made on the 82 last. It was a super tight boot which is strange for me to experience being that I have a shallow, low-volume foot. Yet the 888 last, was very voluminous in the UK7/US7.5 size and while I did not try it, know that I would have been better in the UK6.5/US7 shoe size. But that, for me, should actually be considered a UK6.5/US7.5 as it is super rare that I can ever fit into a US7 for the fact that my true size is a US8 narrow.
Shopping online will never allow you 100% security of getting your shoe size right the first time in any given shoe brand. I do not care what anyone says. It is impossible. But you can have a 95% chance of getting it right if you are careful in studying their UK to US shoe size guide, reading reviews, and emailing customer service to ensure you are correct in your sizing.
While this quick tip is written more in-depth here, you can generally pick up which size you are encountering when attributing the letter next to the size. Most American shoe brands will use a D as the standard width, while British shoes will use either an E or F. Spanish makers, will be similar to the British and often use an E or F as well for their ‘standard’ width fit. If they do, that means that their shoes should also be in UK sizing. You can see this in some of the photos I have added.
If you go off of the rule that UK to US shoe sizes vary by one entire size, chances are you will be making the correct assumption. It is the far and few between that attribute that difference to only a half size. Just like in the main image, typically speaking a UK7 = US8 = EU41. One exception is shown in the image below on a pair of Gaziano & Girling shoes that typically have the half-size rule.