I am making a 4 tired wedding cake. Round, square, round, square. It needs to feed at least 100 people. I feel like some square pans, although bigger, will be to small for the round tier to fit. Make sense? Thanks in advance.
To compute the diagonal of a square (roughly and quickly) take the side measurement times 1 and 1/3.
If you start with a standard 6" round tier on top, (serves 12)
then an 8" square (serves 32).
Now you have to break out the math to figure out how big a round you need next. 8 X 1 1/3 = ~11, so an 11" round comes next (serves ~42)
That can sit on a 12" square, although it would look a little better on a 13" square. The 12" square serves 72.
Four tiers is WAY too much cake.
You can put a round on the same size square, so a larger square under a smaller round will fit just fine.
A 10" square = 50, 9" round = 32, 6" square = 18, & 4" round = 6... that is exactly 100 servings, or 106 including the top tier.