You’ve probably picked up a dozen eggs countless times from the store. But have you ever stopped to think about why those eggs come in cartons of 12, rather than eight, 10, or whatever amount the person selling them judges to be best?

Eggs have long been key parts of the human diet. We’ve likely been stealing and devouring bird eggs since prehistoric times, and scientists estimate that chickens were first domesticated between roughly 8,000 and 3,500 years ago in Southeast Asia. 

Eggs didn’t become mass-produced products until the mid-1900s, when improvements in sanitation, enclosures, and feeding technologies enabled farmers to mass-produce eggs all year round.

Yet it’s believed that in some parts of the world, eggs were being sold by the dozen long before they became grocery store staples. No one is one hundred percent sure where the tradition of selling eggs by the dozen began, but the prevailing theory holds that it has had something to do with the shilling.

Why Eggs Are Sold By the Dozen: It’s All About Convenience

The main consensus as to why eggs are sold by the dozen is that this is because shillings, at least for much of their time in circulation, consisted of twelve pennies. The first shilling was minted in 1504 during the reign of Henry VII, and remained in circulation until it was officially discontinued in 1971. 

Since a shilling was equal to twelve pennies, it would have made sense for merchants and farmers to sell eggs by the dozen, as this meant that one shilling could get you a package of twelve eggs, no change required. In general, 12 is an easy number to split into halves or thirds, making for easy math when it came to splitting and dividing egg purchases, and this may have lent staying power to the practice. This habit made its way over to the American colonies, where it became standard and remains so to this day.

Eggs aren’t sold by the dozen everywhere, though. In parts of Africa and India, they’re still often sold by the piece, and different countries sell different amounts, like packages of eight and 10.

While the number of eggs in a carton has remained consistent over the centuries, the price of eggs certainly has not. In 2021, a dozen eggs could sell for as little as $2 in the U.S., but in early 2025 the price reached historic highs, selling for an average of $6.22 per dozen in the Midwest, per the Federal Reserve. Prices have gone down since, but likely will continue to fluctuate. 

However, it’s probable that eggs will continue to be sold in bunches of 12 for a very long time. Sometimes you just don’t need to mess with a good thing. 

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