It is best to measure your foot to get the best fit for your UGG Boots. The best way to measure your foot is to place your bare foot ( usually your right ) against the wall, use a pencil to mark the top of your toe and the bottom of your heel. Yours UGG Boots should fell snug at first, the sheepskin will press down moulding to the shape of your foot. Our ugg boots and slippers are available in half sizes only. If your feet fall between the sizes, we suggest you choose the bigger one.