EU 42 or EU 43 – Which One is UK Size 9?

Many women with size UK 9 or UK 10 feet find shoe sizing confusing—especially when shopping online and switching between UK and EU conversions. If you’ve ever wondered whether a UK size 9 is an EU 42 or an EU 43, you're not alone.

Understanding Shoe Size Conversions: UK9 is not always EU42 or 43

European and UK sizing systems don’t align perfectly. A UK 9 falls between EU 42 and EU 43, but different brands across the world convert these sizes differently—some rounding up, some down.

Here’s how foot lengths line up:

As shown, a UK 9 is closer to an EU 43, but not quite exact. Some brands label UK 9 as EU 42, others as EU 43—so it's worth checking the actual foot length if you're between sizes or trying a Cocorose London style of Trainer or Ballet flat. As with all footwear, comfort is so important, give yourself some extra wiggle room.

How Brands, like Cocorose London Decide the Fit

Shoe makers use what’s called a “last” (the mould that shapes the shoe) that includes extra length to accommodate foot movement. For a foot length of 270.9mm (UK 9), a last would typically measure between 278mm and 290mm. Consider also the shoe shape and design. Your would not find a last for a shoe with a rounded or almond toe, to the same length as a ballet flat with a more pointed toe. Certainly our lasts for our Clapham leather loafer collection, found here, are longer that our Harrow ballet flat collection - found here. But note of course that we do not have pointed feel like this, so there is space at the toe. This built in variance is why we find a difference between brands, and between shoe designs.

At Cocorose London, we list both UK and EU sizes clearly and update each product page with sizing notes and fit feedback to help you choose confidently.

Tip: If you’re unsure, it’s always best to try. We offer free UK delivery and simple returns to make the process hassle-free.

Measuring Your Feet

If you're unsure about your exact size, start by measuring your feet.

Below I will be adding a details how to guide, a step-by-step guide if you like, to measuring at home.

But please see out sizing chart where we have compiled our recommendations based off our wonderful customer reviews of styles that suit your specific footwear needs.

Cocorose Collection of our designs in EU42 and 43

We have had designs in our collection in size 42 for 14 years, not long after we launched Cocorose London. This was because we build a business suppling into The Netherlands, where demand was high for a larger size. But it took us until 2019 to launch our designs in size EU43. Driven by demand here, particularly at retail events like Spirit of Christmas and meeting more of the demand from our Dutch customers. You can see all the styles we have launched here in our collection, please if we our out of stock or missing your favourite design, please let us know.