People know that there are 12 items in a dozen. What they might not know is that 12 is a judicial number. That's why 12 people are on a jury. Jesus had 12 disciples to parallel it with the 12 tribes of Israel. So, if 12 items are in a dozen, why are there 13 items in a baker's dozen? Most people don't know the answer or the origin of that particular custom.
A baker's dozen
A baker's dozen is a unit of measurement that dates back to England's Middle Ages. It was a serious penalty if bakers made a mistake or deliberately cheating a customer out of the exact number of items he ordered.
During that time, bread was a staple and bakers knew customers would continue buying from them.
Bakers cheated customers by overcharging them or by not putting 12 loaves of Bread in the bag when customers ordered a dozen. Customers noticed and complained. The problem was so bad that there was a public outcry, and kings decided to make it a law for bakers not to cheat their customers.
Bakers who sold fewer than 12 loaves were severely punished. To avoid the punishment, bakers began adding one extra loaf to be absolutely sure the customer would still have 12 item even if he miscounted. In most cases, there was an overcompensation, but it was better than being punished. For that reason, a baker's dozen today is 13 to distinguish it from the regular dozen that includes only 12 items.
The statute and punishment
The statute that was decreed by the kings frightened the bakers so much that they discontinued cheating their customers. To make sure they abided by what was listed in the statute, bakers decided to give customers an extra loaf of bread or other products to make absolutely sure customers had at least 12 items.
It would be helpful to know that a loaf of bread the medieval bakers sold was not like the long loaf we buy from our grocery store. The loaves they sold were very small much like the size of rolls we eat. Therefore, it was easy to make a mistake while counting them.
The punishment depended on where the lawbreaker's shop was located.
Heavy fines were imposed on the bakers if they were caught cheating their customers who needed their products. In a lot of cases, a high fine was not enough punishment. Therefore, it was legal for a Babylonian baker who broke the law to get one or both of his hands chopped off. In other places, there were less severe punishments such as having their business taken away from them. As you can see, cheating a customer was taken very seriously back then. To be on the safe side, bakers didn't mind giving an extra loaf of bread or other products to avoid the heavy fines and punishments.
The baker's dozen custom is not used today in the United States, so when you purchase a dozen doughnuts from Krispy Kreme, don't expect to get more than 12 unless there is a special going on at the time.