ratio

noun

ra·​tio ˈrā-shē-ˌō 

-(ˌ)shō

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

Synonyms

• proportion
• rate

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 on the Web

If 51% of the population is being so underserved, the ratio to opportunity is insane. —Gemma Allen, Forbes, 23 Mar. 2025

Picture quality is decent, with a high contrast ratio and low input lag that's great for gaming. —K. Thor Jensen, PCMAG, 21 Mar. 2025

Breaking down the club's decision to embark on a bold new stadium project — and all the costs that involves Howe has overseen 163 Newcastle matches and boasts a 50.3 per cent win ratio. —Chris Waugh, The Athletic, 21 Mar. 2025

One assumed that the ratio of methane and ethane to water ice is similar to what was measured on Enceladus, while another looked at the ratio found on Comet 67P during the winter. —Victoria Corless, Space.com, 21 Mar. 2025

Word History

Etymology

Latin, computation, reason — more at reason entry 1

First Known Use

1660, in the meaning defined at sense 1a

Phrases Containing ratio

• aspect ratio
• case fatality ratio
• common ratio
• focal ratio
• golden ratio
• gyromagnetic ratio
• loss ratio
• nutritive ratio
• Poisson's ratio
• price-earnings ratio
• ultima ratio

Rhymes for ratio

• acknow
• aglow
• ago
• airglow
• aloe
• altho
• although
• ammo
• backflow
• backhoe
• banjo
• barbeau

Kids Definition

ratio

noun

ra·​tio ˈrā-shō 

-shē-ˌō

plural ratios

1

: the quotient of two numbers or mathematical expressions

the ratio of 6 to 3 may be expressed as 6:3, ⁶⁄₃, and 2

2

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

women outnumbered men in the ratio of three to one

Medical Definition

ratio

noun

ra·​tio ˈrā-(ˌ)shō, -shē-ˌō 

plural ratios

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