ratio

noun ra·tio \ ˈrā-(ˌ)shō , -shē-ˌō \

Definition of ratio

plural ratios

1 a :the indicated quotient of two mathematical expressions

b :the relationship in quantity, amount, or size between two or more things :proportion

2 :the expression of the relative values of gold and silver as determined by a country's currency laws

See ratio defined for English-language learners

See ratio defined for kids

Examples of ratio in a Sentence

What is the length-to-width ratio?
the ratio of students to teachers in the school is nine to one

Recent Examples of ratio from the Web

The mathematicians at Pizzanista! have discovered the golden distribution ratio of sauce, mozzarella, Gran Padano, and basil.

— steffi victorioso, Los Angeles Magazine, "Every Pizza at Pizzanista!, Ranked," 23 Aug. 2017
Other promising areas include variable compression ratios — a technology Nissan plans to introduce next year — and making better use of available fuels.

— norman mayersohn, New York Times, "The Internal Combustion Engine Is Not Dead Yet," 17 Aug. 2017
In determining the rankings, Niche looked at average educator salaries; administration; health and safety; resources and facilities; student-teacher ratio; rate of teacher absenteeism; and teachers in the first or second year.

— AL.com, "20 best places to teach in Alabama," 4 Aug. 2017
That is, the ratio of a circle’s circumference to its diameter is the same, no matter the circle.

— evelyn lamb, Scientific American Blog Network, "Dave Richeson's Favorite Theorem," 3 Aug. 2017
For a country that has struggled to nudge its capital-investment ratio to 15% of GDP—compared with around 30% for India and 28% for Bangladesh in recent years—this gush of Chinese money comes as a godsend.

— The Economist, "One Lifebelt, One RoadChina makes Pakistan an offer it cannot refuse," 22 July 2017
After all, our shelves are stocked with plenty of drugs whose use in pets is similarly unproven and whose risk-benefit ratios are far more suspect.

— patty khuly, miamiherald, "Medical marijuana for ailing dog? Just don’t let him inhale," 19 July 2017
The ratio for S&P 500 members, adding up all their accounts, is a reasonable 1.5 times, slightly higher than a decade ago and lower than in Europe and Asia.

— The Economist, "SchumpeterThe United States of debt," 13 July 2017
But when the applicants came from employee referrals, the hiring ratio improved to 1 in 16 — for the very best odds of landing a job.

— diane stafford, kansascity, "It really is ‘who you know’: Networking is key when job hunting," 13 July 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ratio.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of ratio

Latin, computation, reason — more at reason

NEW! Time Traveler

First Known Use: 1660

See Words from the same year

ratio Synonyms

Synonyms

proportion, rate

Related Words

average; frequency; correspondence; percentage

Near Antonyms

disproportion

Other Mathematics and Statistics Terms

abscissa, denominator, divisor, equilateral, exponent, hypotenuse, logarithm, oblique, radii, rhomb

RATIO Defined for English Language Learners

ratio

noun

Definition of ratio for English Language Learners

: the relationship that exists between the size, number, or amount of two things and that is often represented by two numbers

RATIO Defined for Kids

ratio

noun ra·tio \ ˈrā-shō , -shē-ˌō \

Definition of ratio for Students

plural ratios

:the relationship in number or quantity between two or more things

the ratio of teachers to students

Medical Dictionary

ratio

noun ra·tio \ ˈrā-(ˌ)shō, -shē-ˌō \

medical Definition of ratio

plural ratios

:the relationship in quantity, amount, or size between two or more things — see sex ratio

Learn More about ratio

See words that rhyme with ratio Thesaurus: All synonyms and antonyms for ratio Spanish Central: Translation of ratio Nglish: Translation of ratio for Spanish speakers Britannica English: Translation of ratio for Arabic speakers Britannica.com: Encyclopedia article about ratio

Seen and Heard

What made you want to look up ratio? Please tell us where you read or heard it (including the quote, if possible).

show

ratio

Definition of ratio

Read the Latest from M-W

Examples of ratio in a Sentence

Recent Examples of ratio from the Web

Origin and Etymology of ratio

ratio Synonyms

Synonyms

Related Words

Near Antonyms

Other Mathematics and Statistics Terms

RATIO Defined for English Language Learners

ratio

Definition of ratio for English Language Learners

RATIO Defined for Kids

ratio

Definition of ratio for Students

Medical Dictionary

ratio

medical Definition of ratio

Learn More about ratio

Seen and Heard

Love words? Need even more definitions?

Love words? Need even more definitions?

Words at Play

Ask the Editors

Word Games

Learned Fools: On Names for Students

Trending: NY Times: Trump's Call Ignites 'Imbroglio'

The Exceptions Quiz III

17 English Words that Come From Japanese

Words of the Year: 1066