One size is too big, the other too small!
I didn't know what to put for "runs small, true to size, or runs large," but it required me to put something...i first ordered the xl, and it was ridiculously gianormous. the next time, i ordered a large. i thought the large would either be a perfect fit or still too large, based on how the xl had fit. the large was too tight! i could not believe it! it is too bad, for i love the design and color of this top! i ordered it in the muted red color. if you can find a size that works for you, go for