How do you determine serving sizes for taller cakes. Like 3 layers instead of 2? Thanks
If your cake is 4" tall, regardless of the number of layers, this Wilton chart works great. Standard party sizes are 1.5"x2"x4", and wedding servings are 1"x2"x4". I've heard it mentioned here on CC that @IndyDebi can cut the cake to exactly those dimensions. Which is awesome, because I sure as heck can't!!
If you're referring to even taller cakes, like a 6" or an 8" high cake (I think they're called double barrels...?), I think that those cakes are usually two 3"- or 4"- high cakes stacked on top of each other, properly supported using cake boards and the dowel system of your choice (straws, SPS, and so on...). You'd have to support the additional cake, otherwise I have visions of it collapsing & tumbling down! Those cakes are then split at the cake board, and the number of servings would then be the same as the standard 4" cakes on the Wilton chart. (I've never put together one of these tall cakes, so I am *not* speaking from experience!)
Click on this post by Erica O'Brien for a better explanation of those taller cakes, down in the comments!
As the other poster said, basically the # of servings is the same as a standard 4" tall cake. See, a 4" tall cake can be created with 2, 3 or 4 layers - depending on how tall each layer is. In fact even more 'layer' if they are cut only 1/4" to 1/2" tall. I've seen articles about people using 20 and 12 'layers' but the cake is no more than 1/4" thick, then that much filling is used (usually b'cream or pastry cream); stack up a dozen of those and you have a cake at least 6" tall :) So your ? makes it hard to tell you if things would be different.
Notice what Erica says in one of her posts: ........Wedding cake slice sizes, however, are actually based on the final height of the cake, rather than the number of layers. This chart is based on cake slices that are about 1″ wide, 2″ deep, and 4″ high. (The standard height for a wedding cake is 4″.).......
Also most dessert plates hold a 4" tall cake slice just right - going taller will make plating the serving a problem :(
The trick to being able to cut it 1" x 2" (x 4" tall) is always having the proper measuring tool with you when you cut the cake. And everyone has that tool. Bend your thumb. From your knuckle to the end of your thumb (not counting any long nails you might have one!) is roughly 1". I just bent my thumb and used it to measure two inches in, then bent my thumb again to cut that 2" strip into 1" pieces! :-)