How much bigger should I cut a square cakeboard to accommodate for the icing? This is for a four tiered cake.

Just use the bottom of the pan as a guide.

The last time I did that, the icing totally went over the edge if you know what I mean. I ended up re-cutting boards a little bit bigger but then they were too big. I don't think that these cakes will have a piped border, which if they did would make this question moot.

I always cut mine to the size of the cake itself (no icing). Alot of my cakes have teeny tiny borders so I don't want the board to show. When I cut it to the cake size, I can use my bench scraper perfectly straight up and down to smooth over the icing.

I use Magic Line pans, and I have found that they baked cake upon cooling is exactly 1/4" smaller than the pan size....for example, a 10" pan yields a 9 3/4" cake in diameter.

I had hubby cut me a whole bunch of masonite circles and squares to 1/4" less than the pan size. I use the masonite as a guide to trim my boards, and also to cut parchment paper for the bottom of my pans, makes it quick and easy. He also punched a hole in the very middle of the masonite circles so it's very quick to use it as a guide to punch the middle of my cake board EXACTLY centered when using the SPS system. (Sometimes I'm a hair off when I use the plate itself).

What i do is ice the cake first then cut around with some scissors. It may take a little practice to hold in one hand while cutting with the other, but it works perfectly for me.
hth

As vdrsolo stated , cakes shrink a little while baking. So the board size has to be somewhat less than the pan size.The way she explained it is very clear.

couturecakecreations--

Don't you get small cardboard fibers in your icing doing it that way? If I am understanding correctly, then you don't have a completely covered cardboard. The edges of the cardboard are bare and then covered in icing. Thanks!

I have never had a problem with cardboard pieces being in my icing but I do feel that is a good question to raise. Tonight I actually cut around the iced cake with an exacto knife. it was a lot easier and leaves a vary clean edge. no cardboard pieces.

I can just see myself trying to cut around the cake with an exacto. But...I will give it a try. Oh wait, I typically double my cardboard for 8" and up. I wonder how that will work. I'll try it and let you know. Melissa, your cakes are lovely.