In adidas sneakers, I always wear size 44.5, for example in Stan Smith, Continental, Super Star, etc. The corresponding size in the Rivalry Low is a click tighter, but I don't think it's to the point where I would need a larger size. In winter, with thick socks, it was a bit tight for me. It's a bit of a chunky shoe, but very beautiful and well-made. 5 stars because you usually find it at a good price; I bought it for around €55, so the quality/price ratio is satisfactory!