Standard Catering & Portion Ratios: Standard event catering models allocate approximately 3/8 of a large 14-inch pizza (3 slices) per adult for casual gatherings, rising to 4 to 5 slices for evening celebrations and sports viewing. Standard large pizzas yield 8 slices, whereas extra-large 16-inch pizzas yield 10 slices with approximately 30% greater surface area. Beverage calculations assume 2 to 3 standard units (330ml cans/bottles) per person across a typical 3-hour social gathering.