I was going to say the same thing as OC Richard. Kilts are not made from patterns. That's because a kilt is not made by sewing together multiple cut pieces of cloth, as would be a shirt, jacket, trousers, etc. (your typical clothing items). Rather a kilt is made from a single length of cloth that is pleated and sewn. So rather than following a pattern, you would follow instructions for how to pleat the kilt, accounting for the particular sett size of the tartan, size of the gentleman, etc.

By far the best and most comprehensive source out there (apart from having an actual experienced kilt maker teach you), is The Art of Kiltmaking, which can be purchased several places, including here.