@ Lolobeauty…I’m going to jump in here…if I had a three tier the sizes you are stating, personally, I would triple this recipe. Better to have buttercream left over, then to have to stop mid-stream and start mixing buttercream in the middle of cake decorating!
If you have a 6qt kitchen aid mixer, you should be able to fit a triple recipe in, all at once.
I hope this helps!
Psalm 127:1 Unless the LORD builds the house, the builders labor in vain.
