Why not simply state the length you have but add either: 'Including 2" rise' or 'Excluding 2" rise' as you feel might be appropriate?

One of my favourite Scottish kiltmakers (!) always notes down on his paperwork : Length xx" (incl x" rise). If I am ordering a traditional kilt, the single 'x' is shown as '2', but if I am ordering a hipster or contemporary kilt it is shown as '0'!

Hope that makes sense - I know what I mean!