Order went smooth and the boots arrived in no time. Thanks to the product description and your others' feedbacks who've been there and done it before me, I was aware to go a size up. Then before shipping, the shop contacted me for a double check - I really appreciate this, it's very nice to connect with a dedicated human on the other end of an online purchase. So, yes, we really, really decided for the size up - I generally go for an EU 37 but depending on the brand and model, sometimes even an EU 36 does the job well and for a lot of flats and some UK brands, I learned to opt for EU 38 / UK 4.5 - 5 instead, just as I am on the safer side with a women's US 7. Long story short, for these Talolo wellies, EU 38 was *the* choice to be made. With socks, they provide an almost snug fit, no "swimming" around inside of these wellie boots. I see how with narrow feet, your true side might work well - do keep in mind though wanting for some wiggle room when you intend to wear them for an all day long. Very happy to now be able to add some style to heavy rain and mud!