Total calories: 400 (per slice). Fat grams: 22. Dietary fiber: 4. Carbs: 45. Manufacturer’s suggested retail price: $11.99 for a 16-inch big’un with three toppings. For a company that usually brags about “better ingredients … better pizza,” this time we find Papa John’s livin’ large on us. The Mega XL is all about size. It’s 16 inches across, which they say makes it 30 percent larger than a 14-inch large. It’s so big they have to cut it into 10 slices instead of eight.