I find kilt sizing to be sort of like artillery fire. Take your best first shot then adjust. With any kiltmaker the first kilt is probably gonna be a little off no matter how well you measure and follow the kiltmaker's instructions (and they differ with different kiltmakers).

But once you have the first kilt strapped on you can then communicate the necessary adjustments on your next kilt order and you're dialed in with that kiltmaker since they keep good records. After that you only need to adjust for major weight gain or loss.

If your first kilt from a new kiltmaker is spot on then you're lucky and you done good. One more reason to order a bunch of kilts.