You should think about jettisoning the chain all together, and going with either a leather sporran strap, or leather hangers. Why, you ask? Because chains have tiny sharp edges on each link, and over time, can be rather damaging to your prize possession, your kilt. A number of places sell leather straps, which fit and behave the same way as the chain / strap belt; others have sporran hangers, which attach to the belt, and hang the sporran below.

As a gentleman of some girth, I prefer hangers, as they eliminate the risk of having the sporran strap creep under my belly.