I'm normally 10.5 - but the first pair had way too much heel room which made them feel like slippers - as in, heel is easily slipping out of the back. Returned for size 10 and now they're heavenly. I like throwing on something fast to go out and can't be bothered with laces and socks - especially during the summer. These go great with any kind of shorts - from gym to casual and work nicely with jeans on a warm evening.  Comfortable soul, but that bright green marshmallow-like material gets dirty fast -- particularly toward the toe area. I'm in Manhattan, so no matter how many showers you take a day, this probably can't be avoided.