Why a Baker’s Dozen is 13 Instead of 12

Daniel G asks: Why is a baker’s dozen 13 and not 12?

breadThere are three main theories for why a baker’s dozen is 13 instead of 12, but most think it has its origins in the fact that many societies throughout history have had extremely strict laws concerning baker’s wares, due to the fact that it is fairly easy for bakers to cheat patrons and sell them less than what they think they are getting.

These societies took this very seriously as bread was a primary food source for many people.  For example, in ancient Egypt, should a baker be found to cheat someone, they would have their ear nailed to the door of their bakery. In Babylon, if a baker was found to have sold a “light loaf” to someone, the baker would have his hand chopped off.

Another example was in Britain in the mid-13th century with the establishment of the Assize of Bread and Ale statute, which was in effect all the way up to the 19th century before being repealed by the Statute Law Revision Act of 1863.  The Assize of Bread and Ale statute set the price of ale and what weight a farthing loaf of bread should be.   Specifically it stated:

By the consent of the whole realm of England, the measure of the king was made; that is to say: that an English penny, called a sterling round, and without any clipping, shall weigh thirty-two wheat corns in the midst of the ear, and twenty-pence do make an ounce, and twelve ounces one pound, and eight pounds do make a gallon of wine, and eight gallons of wine do make a London bushel, which is the eighth part of a quarter.

So basically, in terms of bread, setting the relationship between the price of wheat and what the subsequent price of a loaf of bread from a certain quantity of wheat should be.

Even though this statute was enacted at the request of bakers, it still posed a problem for them.  If they happened to accidentally cheat a customer by giving them less than what they were supposed to as outlined by the statute, they were subject to extremely severe fines and punishment, which varied depending on where the lawbreaker lived, but could include, like the Babylonians’ punishment, losing a hand.

As it wasn’t that hard to accidentally cheat a customer, given making a loaf of bread with exacting attributes is nearly impossible by hand without modern day tools, bakers began giving more than what the statute outlined to make sure they went over and never under.  Specifically, in terms of the “baker’s dozen”, if a vendor or other customer were to order a dozen or several dozen loaves of bread from a baker, the baker would give them 13 for every dozen they ordered.  Likewise, when selling quantities of anything, they’d give 13 measures when only 12 were purchased.

This practice eventually made its way into the Worshipful Company of Bakers (London) guild code.  This guild was actually started in the 12th century and had a large part in formulating the rules on the Assize of Bread and Ale statute.

Though the above is generally thought to be the correct origins for a baker’s dozen, there are two alternate theories put forth that are somewhat plausible, though lacking in hard historical evidence and visible progression.  The first is that bakers would sell 13 loaves to vendors, while only charging them for 12 which allowed the vendor to then sell all 13 at full price; thus, they’d earn a 7.7% profit per loaf.  So in this case, vendors were being given a sort of wholesale price, but without breaking the laws outlined in the Assize of Bread and Ale which had no exceptions for allowing a cheaper price to vendors.  This theory has some holes in it, but is quite plausible on the whole.

Yet another theory is that it was simply a product of the way bakers bake bread.  Baking trays tend to have a 3:2 aspect ratio.  The most efficient two-dimensional arrangement then of loaves/biscuits/whatever on such a tray results in 13 items with a 4+5+4 hexagonal arrangement, which avoids corners.  It was important to avoid the corners because the corners of a baking tray will heat up and cool off faster than the edges and the interior, which would result in not cooking anything on the corner evenly with the rest.  This theory doesn’t explain why they’d sell them in batches 13 for the price of 12, but at least explains why they may have commonly made them in batches of 13 in the first place and is still a possible source, or at least contributor, to the “baker’s dozen” if it was fairly universal that baker’s baked things in groups of 13, as is suggested by the theory.

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Bonus Facts:

  • Another common name for a “baker’s dozen” is a “rough rider’s dozen”.
  • The term “baker” dates back to around the year 1000.  Another term that meant the same thing from that time was “bakester”.  This latter word probably referring to female bakers; this is similar to how a “webster” was a female weaver, with the “-ster” ending implying a woman.
  • “Bakester” is where the surname “Baxter” comes from.
  • One might think checking to see if a baker was cheating you on a loaf would be as simple as weighing the loaf, but this was not actually the case.  Bakers had many tricks up their sleeves for cheating customers while having the weight come out more or less correctly.  One such trick was to add a bit of ground sand to the loaf to get the weight just so, while being able to use less wheat.
  • The Assize of Bread and Ale was the first law in British history that regulated the production and sale of food.
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  • Wow, thanks for an interesting piece of info! I liked the theory about baking trays, I think it has a lot of sense for this very issue

  • Where and the heck to do you find all of this stuff? I’ve StumbledUpon your website frequently and am always interested in your posts. I wonder about things like this too, but am constantly amazed at what you are able dig up, especially some of the more obscure posts. Keep it up.

  • i always thought it was just cause they cooked whatever exess they had. that’s why i usually have one more than whatever i bake.

  • I just thought a the extra was for the baker to test what he or she had made.

    That’s why I never buy a bakers dozen that has 13 items. I mean if the baker won’t’ even eat it then it’s probably crap. Or the baker is probably being held hostage. Forced to bake terrible things. I mean leaving the extra one in the dozen is probably their only way of calling out for help from where ever they are being held. Probably.

  • I thought it was so the bakers patron would come to their store instead of someone else’s.

  • I can think of another possible reason, though I dont know how plausible it is. Simply: expecting a loss. Firstly, you dont know if you will occasionally burn an item, or if it just doesnt come out well enough. You may want to make extras to compensate. When people ask for a dozen, you dont want to have only eleven available to sell. You may also want to make extras for yourself, or for your family. After all, you arent going to buy a full dozen off yourself. Lastly, you may want to entice a buyer to your bakery with a taste test.

  • Another theory is that it represents Jesus and the 12 diciples. To make it holy the represent all 13 people at the last supper.

  • I aways thought it was the 13th was payment for baking the 12 for the client

  • If your buy price is 12 somethings for a batch and you sell the batch for 13 somethings then your profit is 1/12 not 1/13 so that would be 8.33%. Love the site 🙂

    • no… the author is correct. you are just looking at it from a different definition of profit.

      if you sell 13 loaves at 10 dollars a loaf, you have 130 dollars. if you only paid 120 dollars then your profit is 1/12 of what you spent (what you are saying),

      but you sold 13 loaves for 130 dollars, made a profit of 10, so 1/13 your total revenue is profit.

      make sense? 1/13 per loaf sold is 1/12 of what you spent 😉

      here are some numbers in case you are still not persuaded:

      120 dollars for 13 loaves = 9.23 per loaf
      sell for 10 dollars each = 10 dollars per loaf

      profit is 10-9.23= .76 cents per loaf

      .76 is 1/13 of 10 (the price you sold each loaf)
      .76 is 1/12 of 9.23 (the price you paid for each loaf)

      so your profit is 1/13 of your revenue which is a 1/12 return on your investment.
      I collected 130 dollars today. 1/13 of that is profit. a 1/12 return on my investment

  • Wrong, wrong, wrong…
    Most of your “facts” are false.

    The reason for the baker’s dozen these days:
    If you drop one, you still have the dozen.

  • If you said it is wrong, then you need to do your history lessons again about Bakery. There is another theory. It is when Baker’s started working on bread, they failed so many twelve times but on the 13th try, bread was made correctly.

  • An alternative explanation is that if a customer ordered a dozen buns or similar items for delivery, then the baker would put thirteen on the tray before sending his boy off with it in case one got dropped (or eaten) on the way to the customer’s house.

  • I vaguely remember someone telling me story when I was a bit younger, maybe in Elementary school? that a parent would send the child up to the bakery to get the bread or whatever baked good, and they would always give a little extra one for the kid to eat on the way home.

  • in the early times, bakers have the bad image of cheating. Because they can always sell customers less without them knowing, so to compensate for this, instead of giving 12 pcs. of bread, they give an extra one piece, just in case the customer will complain.

    • All are good comments. Lexie’s theory is the best. I’m not that old but the baker always gave me an extra one to eat on the way home!

  • I always thought of the Baker’s dozen as being more about mixing and portioning to where an extra item was produced, that 13th cookie or muffin to use up the dough/batter without waste or trying to determine which other item needed more pour.