I had a pair of Forte Traverse MTB shoes size 45 that were a bit big on the heel so I went with size 44. The 44's fit snug on the heel and had good room up on the toes. The only problem was that they were narrow and fit a bit tight. I finally took the wife's advice and ended up exchanging them for these Pearl iZUMi's. I went with size 45. Nice 'n snug on the heel and good toe room and perfect width. I also like the breathable mesh. I'm a casual rider so these were more than enough for my commute to work and my daily ride on the trails.