Pan Size Converter
Converting Standard 12-cup muffin pan to 9x13-inch pan? Find out exactly how to scale your recipe and adjust bake time.
Units
Recipe scaling
scale ingredients up × 2.44
Area ratio: 117 / 48 sq in
If you scale the recipe
Keep the original temperature and bake time
Area scaling keeps the batter depth similar. Start checking doneness about 5 minutes early.
If you keep the full batch
The full batch will be about 41% as deep
Keep the temperature, but start checking early because the thinner layer can bake faster.
Popular conversions
12-cup muffin pan to 9×13 cake pan: practical conversion
The target has 2.44× the base area of the original. Scale the ingredients by that amount to keep batter depth close to the original; the shallower-batter comparison below applies only when you keep the full batch.
| Original recipe | Target-pan amount | Practical handling |
|---|---|---|
| 200 g flour | 488 g | Weighing keeps the scaled amount precise. |
| 3 large eggs | About 7.31 eggs | Beat the eggs, then weigh about 366 g of beaten egg. |
| 1 cup liquid or sugar | 2.44 cups (about 2 1/2 cups) | Use a measuring cup for liquids; weigh dry ingredients where possible. |
If you keep the full batch: shallower batter
With the same 4 cups of batter, the layer is about 1.2 in (3.06 cm) deep in the 12-cup muffin pan, versus 0.49 in (1.25 cm) in the 9×13 cake pan.
Bake-time starting point
For a scaled batch, keep the original temperature and time, then start checking about 5 minutes early. For a full batch in the target pan, plan on about 20–25 minutes for a shallow sheet cake made from a batter that takes about 18–22 minutes as cupcakes. Pan material, recipe density, and the intended texture can shift the final time.
What Matters for This Conversion
- - A full cupcake batch in a 9x13 becomes a shallower sheet cake.
- - For an area-scaled batch, keep the original temperature and start checking about 5 minutes early.
- - For the full, thinner sheet, begin checking early to avoid dry edges.
FAQ
Can I bake cupcake batter in one pan?
Yes. Scale by area to preserve depth, or spread the full batch in a 9x13 for a thinner sheet cake and check it early.
Will bake time be longer?
Not because it is deeper: a full batch in a 9x13 is shallower. Use about 20–25 minutes as a starting point and begin checking early.
Do I need to reduce temperature?
No. Keep the recipe temperature for an area-scaled batch or a thinner sheet; adjust only if your recipe is browning too quickly.
What pan works best?
Pick the pan with area closest to combined cupcake area.