Well I have lost 3 and half stone (well 4 really counting the loss before sw (I keep forgetting that
) and have gone from size 30 to size 24 trousers and 26 tops. I think a stone is meant to be dropping one size but it all depends.
I do think certain weights equal certain sizes just from people in my family being same height (5ft 4) to me I think size 18 = 12 stone and stuff. But we all wear clothes too big for us anyway.
I have gone from wanting to be size 18 to 16 now though as other people I go to sw with have achieved it.