A heavily armored four-turret Renown would approach Hood's size

How much larger would Renown need to be for a 9-inch belt and four twin 15-inch turrets?

Keeping the historical speed with that protection and armament would push the ship toward roughly 32,500 to 35,000 tons, close to Hood territory.

Renown began much lighter than Tiger, so adding a thicker belt and two more heavy guns cannot be treated as a small alteration. The resulting ship would be closer to Hood in scale. Retaining Renown's speed is what drives the displacement so high. A light execution might reach about 32,500 tons, while a more typical build would be closer to 35,000 tons.