How many cake box mixes do I need for 3 9" cakes?

[Olivia]

I know they say one box makes two 9", but I've heard thats just not enough. So if I'm making 3, would 2 boxes be enough, or will I need 3 boxes? (I'm using Pillsbury Moist Supreme Devils Food)

 

[ChesterV]

All the box cake mixes I've seen have all that information on the back of the box.

 

[Diane Lane]

I don't know if you're trying to make some special sort of cake that would be thicker or taller than usual, but one box should be sufficient for 2 9" layers, so for 3 9" layers, 2 boxes should be enough, but I wouldn't use the entire 2nd box, unless as I said, you're trying to make some sort of extra tall/thick cake, in which case you might need to bake it a little longer, since there'll be more volume to cook.