Cake Mix Confusion???

One cake mix will generally fill two 8" round pans, particularly as you're using a modified mix by adding a bit extra to it.  Depending on how high each cake rises, each one may even be high enough to torte, giving you four layers all together.  Depends on the cake itself.

I haven't used boxes since they changed to the smaller sizes, but I would say absolutely not! I would add an egg and a pudding, and the cake would never fill more than a 7" set of pans. Now that they are even smaller, there is no chance. But why don't you just try it?

Ah...see?  You won't get consensus here, either. 

I can tell you now, you will not get 2 8" layers from a box of cake mix, especially since they have reduced  the amt. in  the boxes. You will have to use 2 boxes . adding the pudding will not help to make more batter nor the extra egg. hth

When I use box mixes, I also add the extra egg, pudding, etc.... and get (3) 8" rounds with 2 mixes. One mix isn't enough to get the heigth for a 2" deep pan.

I think ALOT of new cakers come on here want thier questions answered easily without having to do any work to figure it out for themselves. I do not mean to offend the poster, it's just that cake baking has so many variables. The same exact cake made by 2 different people can and often does turn out differently!! So alot of times you can not get one specific answer because there simply isn't one. It is just best to do some work and figure out what will work best for you!! Find a cake size chart, find out how many cups of batter you need to make a 2" deep x 8" diameter cake or whatever size you want. Make your cake mix and measure the batter. Keep a chart for yourself of every  different batter you make and how many cups it makes. This way you will know based on your exact recipes how many cake mixes you need to make the cake size you want.