Dec 29, 2009 05:51 AM
Discussion

### Need help converting cake recipe from 9" round to 14" round (3 layer)

Hi,

I've been asked to make one of my favorite cake recipes (for a 9" round cake) as a larger, 14" round cake for a party (3 tiers). Can someone tell me how to calculate the increase? I also know I need to adjust the leavening differently so it doesn't collapse. Would appreciate any advice or formulas you might have.

Thanks!

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1. Assuming the cakes will be the same thickness, you multiply by the difference in square inches for the size of each pan:

9-inch pan: 3.14 (pi) x radius (4.5 inches) squared = 64 square inches
versus
14-inch pan: 3.14 x 7 squared = 154 square inches

154 divided by 64 = 2.4

Multiply the 9 inch cake by 2.4 to get the 14 inch cake.

4 Replies
1. re: DebL

can u help my daughter with her homework ? LOL ;)

1. re: Jimbosox04

formula for volume of a cylinder -
Pie R squared times Height
Pat

2. re: DebL

we're assuming the pans are the same height here... OP, is this the case?

1. re: Emme

If not, just multiply the final number by the height to get the volume of each. DebL's assumes the height is 1".

1. re: chowser

Thanks for digging that up! Need to bookmark it right away.

1. re: DebL

I think it's a very helpful site in making/cutting large cakes, from serving size to conversions, etc.

2. OK so here are my thoughts on the calcuation.... what you need to calc is not an area (inches squared), but a volume (inches cubed). And, yes if you assume the pan in 1 inch high, the numbers are the same.

So for two 9X1 inches pans you need 128 (2X64 ) cubic inches of batter.
And for three 14X1 pans you need 462 (3X154) cubic inches of batter.

462 divided by 128 = 3.6
You need to multiply your recipe by 3.6.

Anyone concur? Am doing this correctly do you think?

P

i assumed that the OP's recipe made THREE 9-inch layers, not the two that you are assuming. If everything is the same, pan height and number of layers, then DebL's calc would be correct, but your's is correct if the original recipe only made 2 layers.

I have modified a cake recipe in this way to make a 12inch cake and I did not have to adjust the leavening. However, 14 is a pretty big cake, and Rose L.B. has a table in the Cake Bible that tells you how to adjust leavening to convert to larger size pans. And of course it will cook more slowly.

2. OP here. The cake is 1 cake with three layers, each the same thickness as the original so the 2.4 seems correct. I'll have to figure out how to adjust the leavening accordingly. It seems I'll finally have an excuse to purchse RLB's book!

Thank you so much for your help!