I always thought this round plate was a cake plate but after referencing my Avon Cape Cod collection reference book, I see that it is the dinner plate. The diameter is about 11" . This beautiful ruby glass plate is in excellent condition with only a few light scratches. You could use it to serve desserts if you prefer. It is the same size plate that is used as the base of the tidbit two tier server. The dinner plate was produced from 1982 to 1990.