The XL is a UK 16
Reviewed by MKE outside girl from Milwaukee on Thursday, November 13, 2014
I ordered this vest hoping that the Rab site sizing was accurate. The tag says UK 16, which is a US 14. I'm a solid 14 and it fits perfectly. It's even roomy thru the chest, and I'm a 36DD. Don't let the sizing throw you off. Great vest!