I have to make a Whimsical or Topsy Turvey Cake that will serve 40 guest. I swear for the past week I have been searching the web for a cake serving chart that will help me to determine which size cakes to use. Can anyone help me? TIA ( Really, Really appreciate any suggestions.)

Check Wilton's site they have a serving chart on there. That will help you.

I usually take 10 servings off each cake