proportional

1 of 2

noun

pro·​por·​tion·​al prə-ˈpȯr-shnəl 

-shə-nᵊl

: a number or quantity in a proportion

proportional

2 of 2

adjective

1

a

: corresponding in size, degree, or intensity

b

: having the same or a constant ratio

corresponding sides of similar triangles are proportional

2

: regulated or determined in size or degree with reference to proportions

a proportional system of immigration quotas

a proportional font/typeface [=a font/typeface with characters of various widths]

proportionality

prə-ˌpȯr-shə-ˈna-lə-tē 

noun

proportionally

prə-ˈpȯr-shnə-lē 

-shə-nᵊl-ē

adverb

Synonyms

Adjective

• proportionate
• in proportion
• commensurate
• comparable
• balanced

Examples of proportional in a Sentence

Adjective

The features of the face in the drawing are proportional.

the website's popularity increased exponentially, resulting in a proportional increase in advertising revenue

Recent Examples on the Web

Noun

This sensor uses an enzyme that catalyzes glucose to create hydrogen peroxide, which is further oxidized at the electrode to release electrons, thus generating an electrical current proportional to the glucose concentration. —IEEE Spectrum, 25 July 2017

The bottom line: Arkansas would need to add 20 moms to the legislature to achieve representation proportional with the population of the U.S., the report said. —Michael Graff, Axios, 23 Oct. 2024

Adjective

Therefore, the cosmological constant is proportional to the square of the angular velocity of the universe. —Robert Lea, Space.com, 21 June 2025

And the mean size of that bias turns out to be proportional to how big the triangle was. —Steven Strogatz, Quanta Magazine, 12 June 2025

Word History

Etymology

Noun

borrowed from Late Latin prōportiōnāle, noun derivative from neuter of prōportiōnālis proportional entry 2

Adjective

Middle English proporcional, proporcionel, borrowed from Middle French & Late Latin; Middle French proporcionel, borrowed from Late Latin prōportiōnālis, from Latin prōportiōn-, prōportiō "analogy, proper spatial relation between parts" + -ālis -al entry 1 — more at proportion entry 1

First Known Use

Noun

1570, in the meaning defined above

Adjective

14th century, in the meaning defined at sense 1a

Phrases Containing proportional

• directly proportional
• inversely proportional
• mean proportional
• proportional font/typeface
• proportional parts
• proportional representation
• proportional tax

Rhymes for proportional

• torsional

Kids Definition

proportional

adjective

pro·​por·​tion·​al

p(r)ə-ˈpōr-shnəl,

-ˈpȯr-,

-shən-ᵊl

1

a

: being equivalent in size, amount, or strength

b

: having the same or a constant ratio

2

: set with reference to proportions

proportionality

-ˌpōr-shə-ˈnal-ət-ē

-ˌpȯr-

noun

proportionally

-ˈpōr-shnə-lē

-ˈpȯr-

-shən-ᵊl-ē

adverb