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

Wells Fargo’s overall efficiency ratio was also below expectations. —Zev Fima, CNBC, 11 Oct. 2024

Even with earnings expected to decline 1% this year, Signet’s stock looks cheap, priced at 6.3 times earnings, a P/E ratio 33% below its five-year average of 9.4. —Christopher Helman, Forbes, 10 Oct. 2024

City officials will also address density — the ratio of living units to available acreage. —Jim Riccioli, Journal Sentinel, 10 Oct. 2024

In Japan, the age-dependency ratio is 51%, meaning there are 51 elderly people for every 100 working-age adults. —Emily Peck, Axios, 10 Oct. 2024

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

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