I would say your regular size would work for these blazers. I'm 5'5" 150 lbs 36-30-40 and the M fit perfectly. They're very cute, but definitely a lighter fabric (not see-through)--perfect for summer--but more like a smooth cardigan than a structured blazer. They also arrived wrinkled, which isn't a big deal, but keep in mind they will probably require a bit of upkeep. I took a star off for the horrendous smell when I pulled them out of the package (smelled noxious like chemical dye). Left them out on my porch for 2 days to air out and it went away mostly. Overall, very satisfied for the price.