In the past I've found that it's usually between one and two stone per clothes size, if that makes sense. When I say that, I mean per complete clothes size. So if you are, for example, a small size 18 then it may only take a few pounds lost for you to start wearing 16s. But you may have to go another stone and a half or more before you can start wearing 14s. These are just example clothes sizes by the way, not talking about anyone in particular!