I suspect that the problem might be the shaping rather than the actual size.

Having the luxury of being able to make my own clothes I get to try them on during the construction and correct the fitting. I noticed that the back waist was looser than it ought to be from the measurements quite early on but having already done the pleats, I decided to ease in the top edge of the kilt as it was only that top edge which was loose.

Wool fabric is malleable, it is the difference between dressmaking and tailoring for there to be reshaping of the fabric.

I use webbing for the inner layer of the waistband, so it can take a lot of stress, and it can support even my heaviest kilts as long as the shape is correct.

Of course there is an anatomical difference to be considered - but I was checking measurements and pondering for some time over the obvious gap - I suspect it is simply the thickness of the pleats taking up extra room within the volume of the fell rather than any fundamental difference in anatomy. The kilt can't be tightened down enough to hold steady because it is too tubular - adding a belt helps because it is compressing the waistband - squashing those extra inches I remove during the construction.

Anne the Pleater