Why Do Skyscrapers Skip the 13th Floor?

Step into an elevator in an American high-rise, and you might notice something strange. The floor buttons jump straight from 12 to 14. Of course, the 13th floor still exists; it may just go by a different name, like 12A, 14 or M for “mechanical” or “mezzanine.”

The practice is rooted in a centuries-old superstition: the fear of the number 13, or triskaidekaphobia. While the fear may seem irrational, it has left a lasting mark on American architecture.

The origins of triskaidekaphobia are unclear, but mythology and folklore offer some explanations. According to one popular retelling of a Norse legend, Loki arrives uninvited at a feast in Valhalla as the 13th guest, setting in motion events that lead to the death of the god Baldur.

Others trace the number 13's unlucky reputation to the Christian story of the Last Supper, when Jesus shared a final meal with his 12 apostles, including Judas, who later betrayed him. By the late 17th century, the association between 13 dinner guests and misfortune may have helped fuel a superstition that if 13 people gathered at a table, one would die within a year.

Some people think 13 suffers simply because it follows 12, a “complete” or “perfect” number represented by the number of months, clock hours, zodiac signs, Olympian gods and more.

By the time skyscrapers began to rise in the late 1800s, 13’s perceived unluckiness was common enough that some building owners skipped labeling the 13th floor to avoid scaring off superstitious tenants.

Newspaper articles from the turn of the 20th century mention the growing difficulty of renting out spaces on 13th floors. Others reported the development of new office buildings without the dreaded level. Some early high-rises initially included a floor labeled 13, but developers later went to great lengths to renumber the rooms above the 12th floor.

Not all early towers followed this trend, however. The Flatiron Building (1902), Woolworth Building (1913), Chrysler Building (1930) and Empire State Building (1931) all have 13th floors.

Buildings without a labeled 13th floor are still common today. One oft-quoted 2002 estimate from elevator manufacturer Otis Elevator Co. suggested that 85 percent of U.S. buildings with more than 13 floors skipped the unlucky number. However, the company's current press office could not confirm the statistic. A 2024 study of New York City high-rise condo buildings found that only 13.5 percent had a unit with a 13th-floor label.