Go by the number size on the swim suit. I wear a 10/12 and had to get a 3x. I love the suit and joe it looks but it came with tons of scraps on it. Like a rock was just rubbed around on the fabric and cut it up. Ive ordered about 4 suits from them and the first two I thought maybe were a freak thing. Ordered two more same issue. I emailed them for the one bc it was cut up so bad and they never replied. Suit is very cut but poor quality and poor customer service.