Now, MUCH depends on your definition of "kilt."

Belted Plaids/Great Kilts?

ALL levels of things called: "kilt?"

Just decent made ones?

Is scale an issue?
(some WOULD argue one "owns" the kilts for a kilted GI Joe (or, in my case a Batman or a foot tall skunk). I won't PUSH that one.

Also, if one makes their OWN kilts, . . .
-Count only FINISHED ones?
-Do partially finished count?
-What about kilts in material, but not sewn together yet?
----Would that just be a "small belted plaid" right now" anyways?

Anyways, I would say 10-20, based on belted plaids and finished kilts. I have 7 box-pleats finished, one never quite finished, one knife pleat, 2 Sport Kilts "on loan" to others (one of which is more of a lend-lease/give). That makes 10/11. Plus, 5 that WILL become kilts. I also have 6 belted plaids of varying quality (one bought at $1/yard-> which has 9 yards on it, so it is REALLY 2 more disposable belted plaids). Together, that makes 19. PLUS, there is other material I MAY make into either a non-wool kilt, solid kilt, or the like, which pushes it to closer to 20-25.