You use the term ‘Baker’s Dozen’ to refer to thirteen of something.
Example of use: “I’ll take a baker’s dozen of those donuts, please.”
Interesting fact about Baker's Dozen
"Throughout history, bakers have been subject to strict penalties for cheating their clients. To prevent accusations from flying, they often included a little extra, giving 13 loaves if 12 were ordered.
The practice was common during the 12th century and probably originated before then."
