A 10-inch pizza is cut into 6 slices and can feed up to 3 people if you're considering 2 slices per person.  A 10" pizza is often a small pizza from a restaurant, a 12" pizza is a medium and a 14" is a large pizza.  12-inch and 14-inch pizzas are usually cut into 8 slices and can feed up to 4 people (2 slices per person). But, the amount of pizza per person will vary depending on their hunger level and the amount of toppings.  For example, pizza with more toppings will be more filling than plain cheese pizza.