Recipe Pan Size Scaler
Baking in a different pan than the recipe wants? Pick both pans and we’ll find the exact scale factor and rescale every ingredient for you — automatically.
9-inch round → 9×13-inch
×1.84
Multiply every ingredient by 1.84 (about 84% more)
Classic Chocolate Chip Cookies 4⅛ cups (2 1/4 cups) all-purpose flour 1¾ tsp (1 tsp) baking soda 1¾ cup (1 cup) butter, softened 1⅓ cup (3/4 cup) granulated sugar 1⅓ cup (3/4 cup) packed brown sugar 3½ large eggs (2 large eggs) 3⅔ cups (2 cups) chocolate chips Preheat oven to 375°F. Bake for 9 to 11 minutes until golden.
Time & temperature
- Scaling by area keeps the batter at the same depth, so the oven temperature stays the same and the baking time is similar — just start checking a few minutes early.
- You scaled up a lot — make sure the new pan isn’t overfilled (keep it about two-thirds full). If in doubt, split between two pans.
- Deeper pans (loaf, springform) bake slower — lower the temperature by ~15°F (10°C) and add time. Always confirm doneness with a skewer.
How pan scaling works
The trick is to keep the batter at the same depth, so it bakes the same way. That means matching the pans by surface area.
1. Measure area
Round = π × radius². Square & rectangle = length × width.
2. Divide
New area ÷ old area gives the scale factor for every ingredient.
3. Keep temp
Same depth = same temperature; just check doneness a little early.
Common pan conversions
| From | To | Multiply by |
|---|---|---|
| 8-inch round | 9-inch round | 1.27× |
| 9-inch round | 8-inch square | ≈ 1.0× (swap freely) |
| 8-inch square | 9×13 | 1.83× |
| 9-inch round | 9×13 | 1.84× |
| 9×13 | 9-inch round | 0.54× (or split in two) |
| 9×5 loaf | 8½×4½ loaf | 0.85× |
Pan scaling FAQ
How do I scale a recipe for a different pan size?
Compare the two pans by surface area and multiply every ingredient by the ratio. For example, an 8-inch square pan is 64 in² and a 9×13 is 117 in², so you multiply everything by 117 ÷ 64 ≈ 1.83. Scaling by area keeps the batter at the same depth, so it bakes the same way. This tool does the math and rescales the whole recipe for you.
Do I need to change the oven temperature?
Usually no. Because scaling by area keeps the batter at the same depth, the temperature stays the same and the baking time is similar — just start checking a few minutes early. The exception is noticeably deeper pans (like loaf or springform): lower the temperature by about 15°F (10°C) and add time so the center cooks through.
Can I bake an 8-inch recipe in a 9×13 pan?
Yes. An 8-inch square → 9×13 is about 1.83×, and an 8-inch round → 9×13 is about 2.3×. Multiply the ingredients accordingly (this tool does it automatically). Make sure the larger pan isn’t overfilled — keep it about two-thirds full.
What if I don’t have the exact pan the recipe wants?
Use the closest area. Some pans are nearly identical — a 9-inch round (64 in²) and an 8-inch square (64 in²) hold the same amount, so you can swap them with no changes at all. The tool lists each pan’s area so you can judge the closest match.
Will scaling change the baking time?
Only a little, as long as the batter depth stays similar (which area-based scaling ensures). Start checking 5–10 minutes early and judge doneness with a skewer rather than the clock, since every oven and pan behaves slightly differently.
Keep going
More free tools and guides for adapting any recipe.