Some kilt belts are used to suspend the sporran from. I prefer an either/or approach to belts and sporrans. But that's not what this thread is about.

My kilt belt from L & M Highland is about 3" wide, and adjusts and fastens as described a couple of times above. I think it gives a "finished" look to the waist of the kilt, but a sporran gives an equally "finished" look.