This is a good question. And if you are buying a cake, a question you should ask of your baker. Every baker is different when determining the sizing of your cake.
We would love to be able to provide you with the wedding cake of your dreams. I do get a lot of clients that will tell me they saw a cake on our website that was for 350 people and would like us to make the same cake for 75 people. I only wish it were that simple.
If we were to shrink down a cake for 350 to 75 people your cake would not be the same height or diameter. It would actually look very small and not fit the scale of your room. In order for us to make these grand wedding cakes we actually need the portions of cake to be able to do so. (If you are looking to cut costs, adding fake tiers won’t help, it’s the decoration of the cake that costs more than the actual cake itself.)

For us, the amount of guests dictates how many tiers tall your cake will be. (Again this will differ from bakery to bakery, so make sure you ask.) If you have 50 guests we can provide you with a 2 or 3-tiered stacked cake, the same for 75 guests. If you only have 50 guests and you want your cake to be 5 tiers, we won’t do that for you. At this point your cake gets very tall and skinny and the foundation has been compromised. Your cake could easily fall over because the circumference of the base tier is not wide enough. Some bakers are willing to do this but we are not.

If you do only have 75 guests, but you want a cake that looks taller, we can of course do that for you, but it will cost you extra. Always keep that in mind, the more you keep adding to your cake, your dress, your photography package the more the costs will increase.