Comfy knickers and fit well, I am a UK size 16-18 the XL fitted well and weren't tight at all - so they would probably be OK for up to size 20 to be honest. I was however a little disappointed with the fabric as it is quite thick and very heavy when you first get it out of the washing machine, so takes a while to dry; and subsequently when wearing if you sweat a lot they feel damp. The fabric sadly does not have a soft feel (like my hubbies Stepones do :( ). They are not 100% bamboo which was what I was hoping for, the make up is 78% bamboo viscose, 16% polyamid, 6% elastane and when looking on the website I could not find that anywhere - so assumed they were 100%. They feel well made though like they will last.