Wrong pan? Right math.
The recipe wants a 9 inch round and you own an 8 inch square. Pick both pans and get the exact scaling factor.
Pan sizes are the silent cake killer: the same batter is 3 cm deep in one pan and 5 cm in another, and the bake time swings by 20 minutes. This converter compares the surface area of 14 common pans and tells you how to scale the recipe.
Good to know
That is the range cake batter wants. Fuller than two-thirds risks overflow and a sunken center, emptier than half bakes into a sad pancake with dry edges.
If your pan makes the batter noticeably deeper than the original, drop the oven about 15 C / 25 F and expect extra minutes. Shallower batter bakes faster, so start checking early.
Whatever the math says, a skewer in the center coming out with a few moist crumbs is the real done signal. Converted pans are exactly when you trust the tester over the clock.
Cooking guides
Recipes in the Pann app scale their quantities automatically when you change servings, and Cook Mode adjusts the steps to match.