FOr us, it was a balancing act... how much material is enough without being too expensive.

When we started making our "5 yard wool" kilt, we were trying different lengths of fabric on a guy my size (39" waist). We wanted to give the best kilt for the money. We had a pricepoint in mind ($350... between our Semi Trad and Premier) and wanted to have a "good kilt at that price". 4 yards seemed to be (IMHO) OK for me, but our average customer's waist is a 44 (actually 43.8 if you take the average of our custom orders). They'd probably need a little more fabric.

Since 4 yards was a bit too little and 6 yards would push the price up a bit, we made our kilts 5 yards. It's still not as nice of a swing or pleat depth as our Premiers (7.5 to 9 yards), but for $350, it's a pretty solid wool kilt.

I hope that sheds some light on the situation from the USAK angle.