David beat me to it but just to add... the weight of kilt fabric is normally taken as a linear yard by the double width of cloth, so that means essentially 4 linear yards will equal 8 yards for a kilt. However, and it is a big however , depending on how the kilt is made, the final weight could be much greater, allowing for the canvas, linings, and buckles and straps, or perhaps even lesser if it is a short drop length of kilt.And also a kilt labelled 8 yards might not actually be that exact measurement, as it means"about" 8 yards are used, which is largely determined by the size of the sett of the tartan.
But it doesn't sounds to be so wrong to me