How big is the largest pumpkin pie?

As of 2014, the largest pumpkin pie ever baked, according to Guinness World Records, had a diameter of 20 feet. It was baked in New Bremen, Ohio in 2010.

The New Bremen Giant Pumpkin Growers baked the enormous pumpkin pie for the New Bremen Pumpkinfest. It weighed 3,699 pounds and required 440 sheets of dough to form the crust and 187 cans of pumpkin for the custard. The pie far surpassed the previous Guinness world record holder, which was 12 feet in diameter and weighed 2,020 pounds. The world-record pumpkin pie took days to assemble and bake. It was cut into 5,000 slices when it was completed.