how many cake mixes do i use to make a two tiered square cake?(im using the boxes.)the pans are 8 and 12 inches. if anyone has any suggestions please let me know asap! thank you!!!

The 8" square pan would use 4 cups of batter, the 12" pan would use 10 cups based on a 2 inch deep pan for a total of 14 cups of batter. At least thats what I have in a chart from Wilton's web site. If 1 box mix fills an 8x3' pan (5 cups) then you would need 3 boxes and would have a bit left over.

Here's the Wilton chart:
http://www.wilton.com/cakes/making-cakes/baking-wedding-cake-2-inch-pans.cfm

thanks for your help! life savers!