i personally thought this ran small. i’m a little on the thicker side and i’m usually between a small and medium but i usually wear a small in dresses just because i like them short and form fitting. this dress definitely has stretch but it isn’t the easy stretchy kind of material, it reminds me of like a pair of compression shorts almost. this thing is tight and very short! almost too short even for me. again i usually wear smalls and this almost seems like it would be an xs. i was so afraid to order a M but thank God i did! i wish i would have gotten a L but i can make it work. also i’m not afraid of this riding up even with it being so short just because the material keeps you sucked in. i’m also 5’10 for reference.