How Much Hamburger Do I Need For Making BBQ For 75 People?

Think about a good patty is say 1/4 lb so say 4-5 burgers per lb so 20 lbs will make 100 burgers.
That would give you 25 extra for big eatters.  Id say 15-20 lbs of hamburger my friend. Good Luck and don't forget the beens

If you will put 1 hamburger in each sandwich so you could make 80 sandwiches because if some would like to get more than 1 so it's offered

About 15