Free recipe tool
Baking pan converter
Your recipe wants a 9 x 13 and you have two 8-inch squares? Enter both pans to get the ingredient multiplier, or read the pan size chart below.
Pan size chart
Common baking pan sizes and their areas
The interior area decides how much batter a pan takes at the same depth. The second column is the multiplier from a recipe written for a 9 x 13 in pan.
| Pan | From a 9 x 13 | Area (sq in) | Area (cm²) |
|---|---|---|---|
| 8 x 8 in square | × 0.55 | 64 | 413 |
| 9 x 9 in square | × 0.69 | 81 | 523 |
| 11 x 7 in rectangle | × 0.66 | 77 | 497 |
| 9 x 13 in rectangle | × 1 | 117 | 755 |
| 8 in round | × 0.43 | 50.3 | 324 |
| 9 in round | × 0.54 | 63.6 | 410 |
| 10 in round | × 0.67 | 78.5 | 507 |
| 9 x 5 in loaf | × 0.38 | 45 | 290 |
| 8½ x 4½ in loaf | × 0.33 | 38.3 | 247 |
Cake pan size substitutions that work
- One 9 x 13 in pan to two 8 x 8 in squares. 128 sq in against 117: multiplier 1.09. The batter comes out about 9 percent shallower, so it usually fits without changing the recipe.
- One 9 x 13 in pan to two 9 in rounds. 127 sq in against 117: multiplier 1.09. The classic layer-cake swap.
- One 8 x 8 in square to one 9 in round. 64 sq in against 63.6: multiplier 0.99. Same recipe, no change.
- One 9 x 9 in square to one 10 in round. 81 sq in against 78.5: multiplier 0.97.
- One 8 in round to one 9 in round. 50.3 sq in against 63.6: multiplier 1.27. One inch wider is about 27 percent more batter.
- One 8 x 8 in square to one 9 x 13 in pan. 64 sq in against 117: multiplier 1.83. Close to doubling the recipe; a double batch will be a little deeper.
- One 9 x 5 in loaf to one 8½ x 4½ in loaf. 45 sq in against 38.3: multiplier 0.85. Loaf batter is deep, so leave room at the top or fill the smaller pan to the same height and bake the rest as muffins.
How the multiplier is calculated
For the same batter depth, the scale factor is the target interior area divided by the original interior area. Round pans use π × (diameter / 2)². Rectangular pans use length × width. Capacity mode divides the target usable capacity by the original usable capacity, which suits shaped pans such as Bundt or fluted tube pans where an area means little.
Capacity and unit factors follow NIST SP 1020.
This multiplier compares footprint or usable capacity. It does not make pans equivalent or calculate bake time.
Worked example in centimeters
A 20 cm square pan has a 400 cm² footprint. A 25 cm square pan has a 625 cm² footprint, so the ingredient multiplier is 1.5625.
To resize by servings instead of by pan, use the recipe converter. For recipes in cups, the cups to grams converter turns each line into a weight, which is easier to multiply.
Good to know
Pan conversion questions
How do I measure a baking pan?
Measure the inside, from one inside edge to the other across the top. Do not include the rim. Many pans have sloped sides, so the bottom is smaller than the top; the top measurement is the one recipes and labels use.
What does same batter depth mean?
The multiplier keeps the batter as deep in the new pan as it was in the old one. Keep the depth and the bake behaves much like the original; change it and the bake time changes too.
Does the bake time change with a different pan?
Often, yes. A shallower layer of batter tends to bake faster and a deeper one slower, and dark or glass pans brown differently from light metal. This tool does not calculate bake time: start checking earlier than the recipe says and use the recipe's own doneness test.
What should I enter for capacity?
Use the usable capacity stated by the pan's manufacturer, or measure it yourself by filling the pan with water to the level you would fill it with batter and pouring the water into a measuring jug.
How do I apply the multiplier to the recipe?
Multiply every ingredient by it, one line at a time, and write the new amounts down before you start. For an awkward amount such as 1.27 eggs, beat the eggs together and use about that share of the mixture. Weighing makes every line easier.
Note the pan on the recipe's sheet
Write the pan you used and the multiplier next to the recipe in your family binder, so next year's bake starts from what worked. The free plan keeps 10 recipes.