What’s the formula or ratio or magic number for dinnerware rentals?

Question

I’m estimating eighty people for my wedding reception. I need to order plates but I’m not sure what the good amount to rent is.

Is there a formula people use, like half as much more?

A ratio, for every ten people there are twelve plates?

Some sort of magic number?

Answer 1

sit down or buffet? For buffet, my caterer said 1.5 x # of people. Glasses- close to 2xpeople.

Sit down dinner though is 1 set per person