I bought this dress in two colors, the red and the floral green. I'm 5'4" and usually a size 4, but based on other reviewers saying the dress ran a bit small, I ordered a Medium in both.

The red fit perfectly (I might have been able to get away with a small, but I like the comfortable fit of the Medium). It falls just above my ankles, so it's perfect for wearing flats.

The floral green was HUGE. It was a totally different material (one of those crinkly materials), and it was sized like an Extra Large. Not sure if the dress was labeled with the wrong size or if this color just runs large, but needless to say I had to return the floral green.

Love the red one, though! It wrinkles pretty easily, but it's really pretty and comfortable for hot weather, so I don't mind.