quartile

American  

[kwawr-tahyl, -til] / ˈkwɔr taɪl, -tɪl /

noun

1. Statistics. (in a frequency distribution) one of the values of a variable that divides the distribution of the variable into four groups having equal frequencies.

2. Astrology. a quartile aspect.

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adjective

1. Astrology. of or relating to the aspect of two heavenly bodies when their longitudes differ by 90°.

quartile British  

/ ˈkwɔːtaɪl /

noun

1. statistics one of three actual or notional values of a variable dividing its distribution into four groups with equal frequencies

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adjective

1. statistics denoting or relating to a quartile

2. astrology denoting an aspect of two heavenly bodies when their longitudes differ by 90°

3. a quarter part of a distribution

Etymology

Origin of quartile

1500–10; < Medieval Latin quartīlis, equivalent to Latin quart ( us ) fourth + -īlis -ile

Explanation

When statisticians divide things into four equal parts, any one of those parts is called a quartile. You might, for example, hear about a successful school that's in the upper quartile of state test scores. People studying information about how people live — how much money they make, how healthy they are, how much they travel, what their ages are, what TV shows they watch — often separate them into groups for comparison. It's sometimes easier to examine statistics and information when it's divided into quartiles, or fourths. The original use of the word quartile was in astronomy, to mean "ninety degrees apart," from the Latin root word quartus, "fourth."

Example Sentences

See Examples For:

quartile

Meanwhile, the top quartile of earners eventually recovers roughly 94% of theirs.

From MarketWatch ● Jun. 17, 2026

Myers said Chesney would be given financial support that ranked in the top third or top quartile of Big Ten teams.

From Los Angeles Times ● Dec. 11, 2025

Humana expects to return to the top quartile for 2027 star ratings, which would boost its 2028 reimbursements, analysts at Oppenheimer & Co said.

From Barron's ● Oct. 3, 2025

While 59% of American 37-year-olds with parents in the top income quartile were married as of 2019, according to Goldman’s research, only 30% of those from the bottom quartile could say the same.

From The Wall Street Journal ● Sep. 21, 2025

I had now M.C. under quartile of Venus and Sol—both in my second, ergo, I got money by this thing, or suit.

From William Lilly's History of His Life and Times From the Year 1602 to 1681 by Elias Ashmole