How to Spell Out “40”: “Forty” or “Fourty”?

Forty (40) is the number that follows 39 and precedes 41. Though it’s related to the number four (4), the modern spelling of 40 is forty. The older form, fourty, is considered a misspelling today. The modern spelling may reflect a historical pronunciation change.

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Fourty examples

If you catch yourself misspelling the name of this number as fourty, you’re not alone. It’s a common mistake, both in print and online:

“Female grey whales are fighting for their life. Fourty-three female whales are breeding in the group in 2015, a big increase from the 27 female whales in 2004.” —Nature World News

“Fourty years ago when the mayor of Elkhorn was Bill Bartley, he and his council members saw the need for a village seniors complex and residence that would keep area seniors in the community as active members.” —Virden Empire-Advance

Forty examples

Nevertheless, the correct spelling, forty, prevails.

“Forty state legislators oppose a plan to legalize casinos in three Arkansas counties, a group hoping to block votes on the measure announced Monday.” —The Hot Springs Sentinel-Record

“The staff got the surprise of their lives when the note in question came out without ‘forty’ being censored to ‘fourty’ . . . This time the collector stood up and said, ‘I’m sorry, Mr Pati. I checked the spelling of ‘forty’ in the dictionary. You are correct.’” —The New Indian Express

The second quote helps demonstrate how to get to the bottom of the issue. Check a dictionary! You will find that the correct spelling is definitely forty. Dictionaries provide any accepted alternate spellings of words, and there is no acceptable modern variant spelling of forty.

Why is fourty so common?

Why are there so many instances of fourty on the internet? Well, it’s kind of a tricky spelling, especially in compound numbers such as forty-four. Forty actually deviates from the pattern: There’s four, fourteen, and then forty. Afterward there’s four hundred, four thousand, and so on.

What about other related forms? Fortieth is the ordinal form of forty, so there’s no u. On the other hand, fourth is the ordinal form of four, so it is spelled with a u. In fact, that’s a good memory aid to help you differentiate between the two.

Here’s a tip: The u is associated with four and its derivatives, but forty and its derivatives don’t have a u.

Why is forty different?

Forty is unique, but how did it get that way? The Online Etymology Dictionary traces forty to Old English from a Northumbrian word that compounded terms meaning “four” and “group of ten.” As early as 1821, its modern spelling appeared in the expressionforty winks, and three decades later it appeared in forty-niners. In case you’re wondering: forty winks refers to a short nap, and a forty-niner is a person who migrated to California in 1849 to prospect for gold. The San Francisco NFL team is called the 49ers (they tend to use numerals and thereby avoid the forty/fourty problem altogether). You can easily find references to these iconic forty terms in literature. Here’s one:

“If she’ll just stay around the house for a few days and take forty winks of sleep she’ll be as fit as ever.” —F. Scott Fitzgerald, “Gretchen’s Forty Winks”

Don’t be too hard on yourself or others who add that extraneous u to forty. Its spelling is really not intuitive, and there are so many instances of fourty to be found that you could easily think it’s correct. Avoid being fooled by remembering that forty does not have a u.