I ordered these for the man in my life &, having read the reviews, I ordered a smaller size than he normally takes.
He is usually a UK 10/European 44. I initially ordered a 43, but it was far too big.
We then measured his feet & ordered a 41, which fits perfectly!
Make sure you look at the size instructions & scroll down to the unisex size guide.
I'd recommend getting the ruler out first time!
Also, I didn't immediately notice that these aren't leather. I thought Birko-Flor was a style name, not a manmade fibre.
It looks fine, though, so it's not a problem.
He's pleased with the sandal & I'm pleased that he's no longer wearing trainers & socks with his shorts!