What does proportion mean?
Proportion describes a part, share, or amount in relation to something larger. Saying that “a high proportion of people prefer tea” means that a relatively large share of the group shares that preference, without necessarily giving an exact figure. Proportion can also compare two things more generally, as in “the building is largely in proportion to its surroundings,” where it refers to relative size, shape, or arrangement. In mathematics, a proportion is an equality between two ratios, such as 2:3 = 4:6. The word is useful because it emphasizes relationships rather than isolated amounts: a number may be large or small on its own, but its significance often depends on the whole from which it is taken. Related words such as proportionate, proportional, and proportionally express the idea of a relative relationship, while the common phrase “in proportion to” directly describes comparison according to a shared scale.
nounA part, share, or amount considered in relation to the whole. It can also refer to the relative size, extent, or degree of one thing compared with another.
- A part, share, or amount of a whole, especially when considered relative to the total.
- The relative size, extent, degree, or number of one thing compared with another.
- In mathematics, the equality of two ratios; for example, four is to six as two is to three.
"A large proportion of the students supported the proposal."
"The chart shows the proportion of households that own a car."
"The ingredients should be combined in proportion to the number of servings."
The plural is used for separate shares or relative dimensions, and also in the idiomatic expression “in proportion.”
"The proportions of the design changed as the team expanded the layout."
Proportion turns a simple share into a question of balance: what part of the whole is it, and how does it compare with everything else?
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does proportion come from?
Proportion comes from Latin proportio, a noun meaning “a proportion” or “a share,” formed from the stem of porportare, “to carry or convey forth,” with the sense of a portion brought out or apportioned. English borrowed the word in the late Middle English period. Its mathematical sense developed through the comparison of equal ratios, while the general sense of a share or relative amount became established in ordinary usage. The related forms proportionate, proportional, and proportionality continue the Latin root’s idea of measured relationship.
Related word forms
How proportion is actually used
In everyday use, proportion commonly describes a share of a larger group or quantity. In mathematics, it specifically means the equality of two ratios and is often written with a colon, such as 3:4.
Easily confused with proportion
A proportion is a part viewed in relation to a whole, while a portion is simply a part or serving of something.
A percentage is a numerical part per hundred, whereas a proportion can be expressed in several ways and often refers to a relative share generally.