A taco bar is one of the best formats for a crowd because guests build their own, which handles appetite and dietary needs without separate cooking. Plan about a third of a pound of cooked meat per adult, tortillas a little above the taco count because they tear and double up, and a full toppings line of cheese, beans, salsa, lettuce, onion, and lime. Beans double as a filling vegetarian base, so it pays to set the vegetarian share rather than assume everyone eats meat.
For graduations, game days, and anywhere seating is short, walking tacos build the whole thing inside a single-serve chip bag with no plates to manage. The taco calculator swaps tortillas for chip bags by the case when you switch the mode on, so the same headcount gives you either a traditional bar or a no-plates station.