The amount of fabric you need to go round you whan you sit is perhaps rather more than you think - particularly in a stiff fabric which is going to remain in its folds rather than spread out.

Remember that when you sit there needs to be enough fabric in the front of the kilt to go over the thighs as well as across the lap, and that the weight of the small pleats and the rigidity of the fabric will make them tend to fall back on each side of the hips, outside the thighs.

If there is not enough fabric then there might be a tendency for the aprons to be drawn apart, with distinctly draughty consequences. This might also be a problem if you need to step over some obstacle or up onto a kickstep or just to put your foot up to tie a lace.