Right on Robert. Been there... done that!

I always had customers (that were buying the casuals) place a measuring tape through their belt loops in a pair of regular pants. It gave me a better idea of the actual size... gave me a little room to work with... and made them feel better when the size was WAY bigger than they thought. I was able to explain it as being the "extra fabric" from the pants.

Worked like a charm every time!