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

Indeed, like his counterparts, Solomon isn’t necessarily worried about the value of the debt America has accumulated, but rather its debt-to-GDP ratio. —Eleanor Pringle, Fortune, 3 Nov. 2025

First, Mama Cozzi’s Original Thin Pizza has achieved the perfect crust to sauce to cheese to topping ratio. —Tara Massouleh McCay, Southern Living, 1 Nov. 2025

This ratio indicates if your business can cover its debt obligations with its earnings. —Danielle Higley, CNBC, 31 Oct. 2025

Instead of shredding the roast pork, as seen in so many versions — including the Cubano at El Puro — at Azucar, the chefs slice it to better achieve the goal of having the perfect ratio of meat, cheese and accoutrements in each and every bite. —Timothy Depeugh, Charlotte Observer, 30 Oct. 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