Not quite.

The 60" IS the vertical deminsion. It is FINE as is.

The triple would be of the WAIST or HIP (perpendicular to your height).
For my but, it works out to 4 yards. For a friend of mine, who has a 72" waist. he needs AT LEAST 6 yards.

You CAN get more, but the 3x is MINIMAL.

For me, mine are 60" x 4 yards.
I am 6' 2."

Make sense?

The "normal" kilt waist to knee measurement is only relevant when you either put it on OR make a sewn in drawstring, waist, et cetera.