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

And More—Had Homes Destroyed Along With Historic Landmarks Automate Essential Tasks For Scaling Industry Access AI can transform education by addressing coach-to-student ratios and ensuring students receive timely support. —Suzanne Dibianca, Forbes, 10 Jan. 2025

The stock lens has a throw ratio of 0.9-1.5:1, while Valerion was showing off an alternative with a 1.3-2.1:1 throw ratio — better for use in larger rooms — at CES, according to New Atlas. —Andrew Liszewski, The Verge, 10 Jan. 2025

With a home price-to-income ratio of 2.6, homes are well within reach for local buyers. —Mike Winters, CNBC, 9 Jan. 2025

This increase in cost ratio is due to a higher proportion of sales to distributors with lower margins. —Quartz Bot, Quartz, 8 Jan. 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

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