A serving size is 1x2x4 right? So if I make a 2 tier cake each tier should be 4 inches high?

you got it!

That's the usual consensuses

Thank you. I know that sounded dumb I just got confused for a second. When cakes are taller than 4 inches like this picture I got off of the knot .com how do you make and serve them? I guess Im asking do you make a cake 4 inches tall and then 8 inches tall. Does it have to go up like that? What if you make a layer that is 6 inches?

Each of those tiers is 4" tall. Are you asking how to disassemble a tiered cake? You just remove each tier and cut them individually, just like you would a single tier birthday cake.

The cutting surface area is the same on a 6" tall tier as it is on a 4" tall tier.... you just have a taller tier. If your pricing is based on a 4" tall cake (1x2x4) and if you make a 6" tall tier, you really should be charging 50% more per serving since the slice is 50% more cake.

1x2x4 = 8 cubic inches.
1x2x6 = 12 cubic inches = 50% more cake than in the 1x2x4.
So if your standard price is $3/serving for a 4" tall tier, then the price for a 6" tall tier should be $4.50/serving.

You can't get more servings from a 6" cake than you can from a 4" cake .... you just have taller slices. *IF* you try to get more servings, the slices would have to be less than 1" in width, which is one really thin slice of cake.

Thank you. I dont know why I thought the layers looked taller to me.
Yeah less than a 1 inch slice would be really thin.