As David says, depends on proposed use. 13oz will swing and swish almost as well as 16oz. I have two 16oz kilts which I wear for formal events - one in my family tartan for special events and one in all black wool which I wear for my part-time work as a District Court Assessor, though casually I wear 13oz kilts, or lightweight acryllic or polycotton ones. Before my wife became disabled we were into the Scottish Country dancing circuit and I preferred the 13oz weight for dancing. I've also done some piping in 13oz and 16oz kilts, preferring the 13oz in summer and 16oz in winter.