Ive seen reviews about fitting the boot over the calf or even the ease of sliding on. I ordered a 1/2 size big and they're perfect! There is space for thick socks yet they won't slide around with normal socks. I tend to have bigger calves but they're perfect in that area too! Im so happy with these boots and relived as I really wanted them. My advice, order a 1/2 size big and you're golden!