I wear a US size 8, usually size 38.5 in EU sizing, and got these in size 39 in the bright pink color (and the black RUB15s and the camel RUB1s - these boots are that nice). For just slogging around the house, taking the dog out etc., I can get away sock-less or with regular socks, but if I'm going to be walking a lot, I have to wear two pairs of socks to keep my heels from rubbing since they are a half size too big. These seem to be very well designed and made: fully lined, easy to clean, and no leakage so far. The tongue has a multi-fold overlapping system that I presume will keep water out pretty well even if you step in a deep puddle, but I haven't actually tried it. The fit is somewhat adjustable due to the laces, but it's still a little big for me throughout, even with skinny jeans tucked in. The laces make them so easy to get on and back off again without getting your hands wet and muddy. Overall, these are surprisingly comfortable. The first time I wore them I walked around a flea market for three hours with no issues. Like all rain boots, they're pretty clunky; I certainly wouldn't drive in these. My only problem with these boots is that I'd expect them to come in half sizes for a perfect fit at this price.