In general-- how many (boxed) cake mixes would you need to fit into a 12 inch square pan that is either 2 or 3 inches deep.

a 10" square pan?

an 8" square pan??

Just a one time fill to get one layer, left over batter is fine- just trying to get a rough estimate.

I hope this question makes sense- I couldn't find it in the forum.

I just say boxed mixed because it seems to be universal rather than every ones scratch mixes that might be different.

Thanks in advance- you guys and gals are great!!

http://www.wilton.com/cakes/making-cakes/baking-wedding-cake-2-inch-pans.cfm

I use the above chart for how much batter goes in the pan. I don't measure it, usually fill the pans about half full but it works for me, to figure out how many mixes I may need to buy. Also if you need a little more than a mix gives you, you can always use a doctored recipe or extender or something like the WASC recipe.

The only problem with cake mixes is they don't all make the same amount of batter. It varies from brand to brand as well as flavor to flavor.

BC and Phils tend to make 4-5 cups of batter. White is about 4 cups, chocolate is usually in the middle.

DH tends to make 5-6 cups of batter. White is around 5 cups, chocolate and others in the middle usually, and the only one I've seen make a full 6 cups is the Golden Butter.

The Rebecca Sutterby WASC recipe (2 boxes BC cake mix) makes 13 cups of batter (measured it last week as I had multiple cakes/cupcakes to do and needed to know). The Wilton batter chart is pretty accurate but it will also depend on the type of batter as some rise more than others. I agree with TexasSugar - figure out how many cups your pan holds and fill it halfway. When in doubt put a sheet pan or a layer of foil on the bottom rack of your oven just in case of spillage.
The other thing I've been doing is marking the fill amounts on the bottom of my pans - saves time later.