I am going to do an 80th birthday party cake for my father in law. There are 80 people invited but I thought I might want to make it to serve around 95 or so just to be on the safe side...and if people want seconds. I was hoping to do a 2 tier but don't think that will work, so probably 3 tier. Can someone please help me on getting the right tier sizes for this cake. I don't want the slices to be tiny like for a wedding, and I was hoping not to go bigger than 12" if possible on the bottom tier. Not sure if that is possible. Thanks!

what shape pans do you want to use? e.g. round or square?

There are so many ways one could go it would be very helpful if you give us an idea of that size and shape pans you have to use.

It will be round I believe. Would like to do just a 2 tier if I can pull it off and feed that many people, but don't know if that will work. I will do a 3 tier if I need to.

Well, a 12x16 (or 1x 4" sheet topped with an 8x4" round would do it.
OR 12, 10,8 (each 4" tall) should also.

80 people invited, or 80 people attending? Also, how many of those 80 people are elderly? They're likely to want quite small pieces IME. 80 "party" size servings seems like it should be more than enough if it's 80 invited.

Still, if you'd rather do only two tiers, you're probably going to have to go bigger than 12" on the bottom. 14 on the bottom plus 8, 9, or 10 on top would do it.

Or what about doing a somewhat smaller two-tier for display, plus a "kitchen" sheet to be cut if and as needed?

Holly

Thanks for your suggestions. Holly - 80 people invited. I figured better to have cake left over than not enough but you make a good point. I'm thinking I might go with a 3 tier since I don't know how a 2 tier will look with such big sizes...so suggestions for 3 tier sizes?

Use this: http://shinymetalobjects.net/cake/calculator/cakulator.cgi

What a great cake calculator! Thanks!