I got asked this question today and was frumped Soooo I thought I would call on the CC community of cakers and see what you all have to say.
Question:

How many boxes of cake would you need to do a 12",10",8" and 6" tiered cake? All cakes torted and filled. Anc they don't want to extend the cake with any fillers.

What shape are the tiers? That will make a difference in how much batter it takes to fill the pans. Are you saying they want just straight box cakes, no add-ins or extenders to make more batter? You will probably need close to 20 boxes of cake mix and that's a rough guess.

the cakes are apparently going to be square I believe is what was asked of me. And yes, just good all boxed cake. Ok I do have to confess to 1 thing. ..they asked me to do the cake...I quoted the price....not in her budge She calls me back and says she's gonna make her own cake...she saw how it's done on youtube...I wished her luck...that's when she asked. I have never made just boxed cake for a wedding before......so I have no idea. All I could tell her was that I thought that a box cake made about 3cups of batter...but I'm not even sure on that.

A box mix makes 4-5 cups of batter but it depends on the brand.
She'll need about 45 cups of batter for those sizes - she should check her box mixes for the amount each one makes and calculate from there.
I'd say at least 12 boxes minimum with a few extras on hand just in case something goes wrong.

Please let us know when she calls you in a panic.

i think a boxed cake makes 4.5 cups of batter...I wish her luck, too. It's going to take more than You Tube to make a wedding cake. I hope she has a heavy duty stand mixer, because she's going to be mixing a lot of cake mix.

A box mix makes between 4 and 6 cups batter depending not only on the brand but also the flavor.

DH makes 5-6 cups. Golden butter makes 6. White is close to 5 and chocolate about 5.5.

BC and Pilsbury make 4-5 cups. White being on the lower side, chocolate higher.

My first tiered cake was straight box mix - as long as the cakes are level and she uses the supports correctly, she'll be able to tier box cake.

Of course, this is assuming she knows how to perfectly level all the layers & tiers and knows how to correctly insert the supports. And has the time to bake, level, torte, fill, ice, dowel, stack, and decorate the cakes with her wedding looming. [/quote]

LOL ohhh yes I'm sure she knows all about that I'm sure she knows all about sketching out a plan,making the gumpaste roses, applying the ribbon. Well I emailed her and told her that from what I can figure out..she needs to look on the box and find out how many cups of batter that cake mix uses. I also told her that she's lookin to use anywhere from 15 to 20 boxes. Wished her good luck and told her I'm sure she would do just fine. hmmmm is that bad.....maybe not..I'm tired our art being refered to as just cake. Then make the &^%%$$ cake, then come tell me my quote was too high!!!! WOW factor don't come cheap.

It's not the cake that supports the upper tiers, it's the support system. I've baked for over 30 years using straight-from-the-box mixes and they stack just fine. It's not the cake .... it's the support system. You can stack a cake of jello if your support system is ok.

I use Betty Crocker and for a 6/8/10/12 square cake, the number of mixes I'd use for each 2-pans (meaning I'm baking two 6", two 8", etc) are 1/1.5/3/4 for a total of 9.5 (rounded to 10 of course).

And I never measure by cups. (geesh, what a mess and I'm just not taking the time to go thru that!). I measure by boxes. A cake mix is one batch. A 10" round takes one batch (mix). Two 10" rounds take 2 batches (2 mixes). Etc. I fill the pan between 1/2 and 2/3's full and bake.

Here's a great website someone posted in another thread for calculations:

http://shinymetalobjects.net/cake/calculator/cake_calculator.cgi