Changing shape for baking: compare the area of the bottom

Useful to know

Changing a baking tin changes the area over which the batter is distributed. King Arthur considers pan dimensions when adapting a recipe rather than relying only on a similar-looking shape. [1]

For a simple example, a 20 × 20 cm base has an area of 400 cm², while a 20 × 30 cm base has 600 cm². The same amount of batter will therefore have a different depth. Area is a starting point, not a complete baking-time formula. Depth, material and the recipe’s doneness checks still matter.