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 of ratio

• 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

Adrienne Andrews, an obstetrics nurse, said UPMC hasn't been following national standards set for nurse-to-patient ratios. — Ricky Sayer, CBS News, 31 July 2026

If the logic is that those who lived through those days won’t need any explanation, the flaw is that four decades on, the ratio of people who clearly remember Lockerbie to those who don’t is only shrinking. — Angie Han, HollywoodReporter, 30 July 2026

At the state level, a July 2026 law in Utah prohibits 1-1 device-per-student ratios for students in kindergarten to third grade. — Janice Mak, The Conversation, 30 July 2026

Even with $41 billion in quarterly capital expenditures, the convergence of commercial cloud revenue growth and further capex growth in July 2027 could mean a higher price-to-earnings ratio—for investors willing to pay more for the stock. — Amanda Gerut, Fortune, 30 July 2026

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