12" square and 8" square. Like alot of other Spong Bob cakes. I used Ideas from one cake and another here on CC. Thanks for all the ideas. wanted it stacked different, but the conners hung over if i turned the top tier. It needed to be 6",but all I could find was an 8".Still the birthday boy liked it and that's what matters. Pineapple house was rice crispy treat. I need some practice on that. Thanks for looking.