i think you have the math wrong, its something like multiply the head size of the drum by pi (3.12"). a kit that size can be done in about 3 sheets or so
Here's how I figure it will work with a sheet and a half:
- The 12x54" half-sheet will do the 12x15" floor tom.
- The 24x54" full sheet will be cut into two portions: one that is 14x54", and one that is 10x54".
- The 14x54" sheet will cover all but 9" of the bass drum's circumference.
- From the remaining 10x54" portion, I'll cut a 10x14" sheet; this will be enough to cover the remainder of the bass drum with a half-inch overlap at each seam.
- That leaves a 10x40" piece left over. From this, I'll cut an 8x39" piece to wrap the 8x12 tom.
- The remaining 2x40" will be used to make 1/2" bass hoop inlays.
And voila! Drum re-wrapping on the cheap. :)