I am needing a two tier cake to serve at least 20 people. Shouldn't a two layer nine inch and a two layer six inch work ok for this? Thanks. RosieC

I think that would be too much cake. I would do either a 7/5 or an 8/5 inch stacked round cake.

Since the tiers will be double layered the slices will be pretty chunky anyway.

I know there are several different serving charts out there, but I usually use Earlene's, (her serving sizes are a little more generous than Wilton's) and a two-layer 9 inch serves 22, while a two-layer 6 inch serves 8. Here's the chart I follow, but as I said, many others have their own favorites.....

http://www.earlenescakes.com/ckserchart.htm