Size guide isn't helpful.
The size guide tool recommended the size 9 or 10 to me (10 as best fit) which was supposed to equate to a size 41, so I ordered the 10 to be on the safe side as I'm definitely a 41, and on the sole actual shoe when it arrived, it shows the US and EU sizes and equates the 10 to a 40, and I'd say it is a 40 in size.
So I don't know why the size guide doesn't account for that. Have to send back as too small.