You should only move the buckleson the right and the strap on the underapron/left. You can move them sometimes up to a couple inches each, depending on whether you have tartan tabs holding the buckkles or leather straps holding the buckles and how long your leather straps are. Tartan is harder because you would like to try to keep the lines aligned with teh tartan on the kilt and buckle but may not be able to. The hole for the under apron strap does not need to move. I have had two different kilts each brought in by 2 inches at the waist, and they look and work fine. I don't think you would want to go much further thanthat though, becasue the aprons begin to wrap around your sides too much after that.