How a cake pan converter works
A cake pan converter tells you how much batter a new pan needs compared with the pan in your recipe. You enter both pans and read one number: the scale factor. Multiply every ingredient by that number and the cake fills the new pan to the same depth. Pan size is the most common reason a good recipe fails, so this one number saves a lot of waste.
The math is simple. Find the volume of each pan (the area times the depth), then divide the new volume by the old one. When both pans are the same depth, this is the same as dividing the areas. This tool does it for you, and it also handles bundt pans and several pans at once.
How to convert a recipe to a different pan size
- Choose inches or centimeters.
- Under "Pan in the recipe," pick the shape and the size the recipe names.
- Under "Pan you will use," pick the pan you own.
- Read the scale factor. It updates as you type.
- Paste the ingredient list. Each line is scaled and rounded to amounts you can measure.
- Add the bake time and oven temperature for a guide to the new baking time.
Worked example: 8 inch round to 9 inch round
An 8 inch round pan has an area of 50.3 square inches. A 9 inch round has 63.6 square inches. Divide 63.6 by 50.3 and you get 1.27. Every ingredient goes up by 27%.
- 1 1/2 cups flour becomes 1 7/8 cups.
- 1 cup sugar becomes 1 1/4 cups.
- 1/2 cup butter becomes 5/8 cup.
- 2 eggs becomes 2 1/2 eggs. Beat one extra egg and use half of it.
The batter depth stays the same, so the oven stays at 350°F. Check the cake a few minutes early, because a wider cake can finish sooner.
Swap a round pan for a square or rectangular pan
Shape does not change the method. A 9 inch square pan is 81 square inches, which is 27% more than a 9 inch round. An 8 inch square is 64 square inches, almost the same as a 9 inch round at 63.6, so those two swap with no change. Use the swap button to flip the two pans and see the reverse factor. Set the number of pans on each side when a recipe uses two layers and you want to bake one sheet cake.
Common cake pan conversions
These factors assume both pans are filled to the same depth. Use them as a quick check, or type your own sizes above.
| Recipe pan | Your pan | Multiply by |
|---|---|---|
| 8" round | 9" round | 1.27 |
| 9" round | 8" round | 0.79 |
| 8" round | 10" round | 1.56 |
| 9" round | 10" round | 1.23 |
| 8" round | 8" square | 1.27 |
| 9" round | 9" square | 1.27 |
| 8" square | 9x13" | 1.83 |
| 9x13" | 9" square | 0.69 |
| 9" square | 9x13" | 1.44 |
| 9x13" | two 8" rounds | 0.86 |
| two 8" rounds | 9x13" | 1.16 |
| 9x13" | 12 cup bundt | 0.74 |
A 9x13 pan is 117 square inches. A 9 inch square is 81. A 9x5 loaf pan is 45.
Area or volume?
Most charts compare area only. That works when both pans are the same depth, and most cake pans are about 2 inches deep. A deep pan holds more than its area suggests. This tool compares volume, so you can set the depth of each pan. It also compares bundt and tube pans by their capacity in cups. Sheet pans are only 1 inch deep, but the tool fills them to the same depth as a cake pan (2 inches) unless you change the depth. Lower the depth for a thinner sheet cake.
Adjust the bake time and temperature
Batter depth matters more than pan size for baking time. When the batter is deeper than in the recipe, the middle sets later than the edges. Lower the oven by about 25°F, bake longer and tent the top with foil if it browns too fast. When the batter is thinner, keep the temperature and start checking early. The tool gives a time range, but it is a guide. Ovens differ, and a toothpick that comes out clean is the real test.
Tips for better results
- Fill pans no more than two thirds full. Bake extra batter as cupcakes.
- Use the pan sizes printed on the pan or the box. Measure across the inside, from edge to edge.
- Weigh ingredients when you can. Grams scale more exactly than cups.
- Scale eggs last. Beat an egg and measure out half when you need half.
- For three layers from a two-layer recipe, set the number of pans to 3 on your side.
You will also see this tool called a cake tin converter outside the US. Use the centimeters button for metric tins. The oven has its own °F and °C buttons.