I do funeral lunches for the church and have done lots of parties of my own for 50 or more...
No time right now to figure it out....but email me if I forget to return to this thread and ask...
Got to go prepare a lunch for 120 right now.
Linda C

A lot depends upon who will be attending! If this is 50 21 year old kidz, especially boys, they will eat a lot more than 50 elderly relatives or toddler cousins. Also it will depend if they are doing other things (e.g., swimming, softball) or just eating the whole time.

You can relax a little more about amounts if you choose stuff that can be frozen for another time, or if you have a place you like to donate leftovers, like a shelter.

I think it is simpler to calculate amounts, and you need to buy less, if you don't have so many choices. You have 4 meat dishes, pizza, and potato salad. I would eliminate two or three of the meat dishes and pizza and add some kind of vegetable -- maybe a green salad -- and some fruit. My kidz' friends always seem to love grapes, and that's so much easier than cutting up fruit salad. Cut big bunches into little bunches and put them in a big bowl or two.

Don't forget to include some diet soda in your mix, although I guess the iced tea would serve the purpose if it's not presweetened.

Sounds like a fun party! You are a nice mom.