These shoes do run small, I listened to other reviews and ordered one size up. Glad I did, as these do fit OK just a tad tight. They are feather light and quite comfortable. I have been wearing this style shoe (toe shoes) since very beginning and I have always worn a size 41 but Vibram has changed the sizing for their toe shoes! The 42 fits like the old 41, I do not understand this and give DARTS not Hearts to vibram because of this! All this does is sew confusion to their customers who often have to return the shoes for a different size if it is available! SHAME AND CONDEMNATION to you Vibram!