Pan Size Converter
Recipe calls for a 9×13 but you only have an 8×8? Pick both pans below and this converter compares their surface areas to give you a scaling factor for the batter, plus what to watch as it bakes. Same-depth pans scale cleanly by area; the notes below cover the exceptions.
Pick two pans to compare.
Common pan sizes and areas
| Pan | Area | Closest matches |
|---|---|---|
| 8 × 8 inch square | 64 sq in | 9-inch round (64 sq in) |
| 9 × 9 inch square | 81 sq in | 10-inch round (79 sq in) |
| 9 × 13 inch rectangle | 117 sq in | Two 8-inch rounds (101 sq in, slightly thicker) |
| 8-inch round | 50 sq in | Half a 9×13 (59 sq in) |
| 9-inch round | 64 sq in | 8×8 square (64 sq in) |
| 10-inch round | 79 sq in | 9×9 square (81 sq in) |
| 9 × 5 inch loaf | 45 sq in | 8.5×4.5 loaf (38 sq in, fills deeper) |
What area scaling can and can't do
- Batter depth changes bake time: a thinner layer bakes faster; start checking 5-10 minutes early. A deeper layer needs longer at the same temperature, not a hotter oven.
- Don't fill past two-thirds: if the factor says 1.5× but that would overflow your pan, bake the extra as cupcakes.
- Round vs square corners: areas can match, but square pans bake corners faster; expect slightly earlier edges.
- Loaves and bundts are depth-critical: for those, match volume rather than area when you can, and treat the factor as a starting point.
Common questions
Can I use a 9-inch round instead of an 8×8 square?
Yes, and it's the cleanest swap in baking: both are 64 square inches, so the batter depth and bake time stay essentially the same.
How do I halve a 9×13 recipe?
An 8×8 pan is 64 square inches to the 9×13's 117, which is 55 percent, close enough to half. Halve the recipe, bake in the 8×8, and start checking a few minutes early since ovens vary.
Does doubling a recipe double the bake time?
No. If you double into a pan with double the area, the depth stays the same and the time barely changes. Time stretches when the batter gets deeper, and even then it's more like 15-25 percent longer, not double; bake by tester, not timer.