What Is a Baker's Dozen? Why It Means 13

A baker's dozen is 13: a dozen plus one extra. If a bakery offers a baker's dozen of rolls, you should receive thirteen rolls. Merriam-Webster gives the same straightforward definition.

Why the extra loaf?

The Worshipful Company of Bakers' history connects the custom with avoiding short weight. Bakers supplied an extra piece of bread with a loaf, or thirteen loaves when a customer bought twelve, to give a margin above the required weight.

The Company also describes its role in enforcing bread regulations and links the Assize Laws to 1266. That is the historical setting for the familiar extra-loaf explanation. It does not give us a precise date when someone first said “baker's dozen.”

When did the phrase appear?

Merriam-Webster dates its first known use to 1596, centuries after the medieval regulations. A custom and the name later used for it can have different histories. The extra-loaf account explains why thirteen made sense to bakers; the dictionary date tells us when the expression is first known to appear in English.

What it means when you buy or bake

Today the phrase tells you a quantity, whether you are buying bread, doughnuts or cookies. An ordinary dozen is twelve; a baker's dozen is thirteen.