Cookies & Bars 8″→13″
Brownie & Bar Pan Calculator
Can I bake 8x8 brownies in a 9x13? Yes: make 1.8 times the recipe, or bake the original thinner and check 10 minutes early.
Bake an 8x8 brownie recipe in a 9x13 or the other way around, then cut the slab into the number of bars you need: rows, columns and the size of each piece.
How to use it
- Pick the recipe's pan and the pan you'll use.
- Enter how many pieces you want.
- Scale the recipe by the multiplier and cut along the grid shown.
How it works
Pans are compared by inside area: a 9x13 has 117 sq in, an 8x8 has 64, so it needs 1.83 times the recipe for the same thickness.
The cutting grid picks rows and columns that give at least your number of near-square pieces with the fewest extras.
If you don't scale, the bars come out thinner or thicker and bake faster or slower.
Assumptions and limits
- Straight-sided pans, measured inside.
- Same batter depth as the recipe.
- A clean knife wiped between cuts.
Sources reviewed October 23, 2026.
Tips
- Line the pan with a parchment sling for easy lifting.
- Cool completely and chill before cutting for clean edges.
- Glass and dark pans bake faster: lower the oven 25°F.
Recipes to try it with
Questions
Can I bake 8x8 brownies in a 9x13?
Yes: make 1.8 times the recipe, or bake the original thinner and check 10 minutes early.
How do I cut 24 brownies from a 9x13?
4 rows by 6 columns gives pieces about 2¼ inches square.
How do I cut brownies cleanly?
Chill the slab, use a long sharp knife, and wipe it between cuts.