You-er than you trainers - a little generous, if you're between size down, or wear with big socks.
Good things - true to size, super comfy and padded inside
Up up up with a fish - true to size, i have plenty of room for good socks
Dr Suess Shoes - true to size, like sulus, comfy inside
The cat in the hat boots - slim fit on the leg, and slighty small in the foot, i could go from a 39 to a 40 in these and wear a sock and they would be better
Thing 1 Thing 2 shoes - a little small, but the 40 were too big so i would stick with my normal size, but if you're between go bigger.