Brownie Pan Size Calculator
Scale a brownie or bar cookie recipe from one pan size to another.
Calculates the exact ingredient multiplier when switching between common pan dimensions.
Brownies, blondies, and bar cookies spread to fill the pan. The batter depth — and therefore the bake time and texture — depends on the ratio of batter volume to pan area.
When you switch pan sizes, you scale all ingredients by the area ratio. If the new pan has 1.83 times the area of the old pan, you need 1.83x as much of every ingredient.
Scaling factor = new pan area / original pan area
Common pan areas (inches squared):
- 6x6: 36 sq in (makes thin bars in small batches)
- 8x8: 64 sq in (the classic brownie pan)
- 9x9: 81 sq in
- 7x11: 77 sq in
- 8x12: 96 sq in
- 9x13: 117 sq in (standard sheet cake pan)
- 11x15: 165 sq in (half-sheet)
When you scale the recipe proportionally, the batter depth in the new pan stays roughly the same as in the original — so baking time should be similar. The main exception: if you end up with a much shallower or deeper layer than intended, adjust time by 5-10 minutes and use a toothpick test.
Temperature stays the same regardless of pan size.
A practical tip: if you are scaling up for a crowd, the 9x13 is almost exactly 1.83x the 8x8. So an 8x8 recipe that calls for 2 eggs becomes 3.66 eggs — round to 4 and accept that the 9x13 batch will be very slightly richer.
Silicone pans and glass pans conduct heat differently from metal. If you are switching materials in addition to sizes, lower the oven temperature by 25°F and check for doneness a few minutes early.