I wear a 1/2 in pants (sometimes a 0) and an XS or S on top and this suit was tight - just a little. The bottoms are OK as far as cut and fit (a little tight... but that's OK for swimming). The top is kinda weird. It seems 1) a little small, and 2) it comes up too high towards the neck. It seems like the bottom seam below the bust is too high, like I may have to pull it down while wearing it. I don't have a large chest (A cup) - maybe it would feel more comfortable on a bustier top.. ? I feel like it is going to ride up...
It is made well... both pieces are lined and stitching is good. Overall a great buy... I only bought it to swim laps ( I used to be a lifeguard...) So it certainly will do the job!
I wish I had ordered a medium... but the size chart said that even a small would be too large according to my waist,chest,hip measurements....