My daughter asked for a medium based on how a different style of Kerrits pants fit and they ended up being quite a bit too big for her. She still has room to grow in the small, but they're great for her. They were a gift and I really appreciated that I was given a gift card for the return before I'd even mailed it in order to get the correct size shipped quickly. That was amazing customer service.
Rated 1 on a scale of minus 2 to 2, where minus 2 is Runs Small, 0 is True to Size and 2 is Runs Big