1 inch equals 2.54 cm. The thickness is equivalent. The diameter of a 6-inch cake is 2.54cm times 6 equals15.24cm, and the diameter of a 4-inch cake is 2.54cm times 4 equals10.16cm.

Wedding cake, it is said that it first appeared in ancient Rome. The word cake comes from English. Its original meaning is flat bread, and it also means "happiness".

Extended data:

In the dark ages of Europe, these rare raw materials were only available to monks and nobles, and their pastry creations were honey gingerbread and flat hard biscuits. Slowly, with the frequent trade, the eating habits of western countries have changed completely.

Soldiers and Arab businessmen returning home from the Crusades spread the use of spices and recipes in the Middle East. In several major commercial centers in Central Europe, bakers' trade associations have also been organized. At the end of the middle century, spices have been widely used by wealthy families all over Europe, which has further enhanced the imaginative pastry baking technology. When nuts and sugar became popular, almond paste became popular. This almond paste was baked in a relief mold made of wood carving, and the patterns on the mold were related to religious teachings.