Copy ∝ in one tap, or pick from 34 rows: y∝x, ∝1/x, ratio signs, near relations and look-alikes.
Proportional Symbol Copy Paste
∝Proportional toU+221DReady to copy
34 proportion signs. Tap any value to copy it.
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34 proportion signs. A character and its name both copy the character. A code copies the code.
Character
Name
Code point
Alt code
Option keys
HTML
LaTeX
U+221D. y ∝ x says that y is a constant multiple of x. The sign is credited to William Emerson, 1768. ∝ in HTML and \propto in LaTeX. It has no Alt code and no Option key.
Made of U+0079, U+221D and U+0078. Direct proportion: there is a constant k with y = kx. Swap in your own letters.
Made of U+221D, U+0031, U+002F and U+0078. Inverse proportion is written y ∝ 1/x, which means that the product xy stays constant. Put your own letter in front.
U+223C. Unicode's first alias: varies with (proportional to). y ∼ x is the second way to write a proportion, except in Japanese texts, where the tilde is kept for intervals. ∼ in HTML and \sim in LaTeX.
U+2237. The as in a is to b as c is to d, written A:B∷C:D. Its table of maths symbols by date credits the sign to William Oughtred, 1628. ∷ in HTML.
U+2236. The is to of the same sentence. Unicode's note: preferred to the colon for division or scale in mathematical use. ∶ in HTML.
Made of U+0079, U+003D, U+006B and U+0078. The equation behind y ∝ x. k is the constant of proportionality, or constant of variation, and equals the ratio y/x.
U+03B1. A letter, not the sign: ∝ is not to be confused with alpha, and Unicode cross-references the two. Alt+224 on a number pad, α in HTML and \alpha in LaTeX.
U+221E. A different sign, for a quantity without bound and not for a relation. Alt+236 on a number pad, Option+5 on a U.S. layout, ∞ in HTML and \infty in LaTeX.
U+2248. Roughly equal, which is a different claim: proportional quantities keep a ratio and need not be near each other. Alt+247 on a number pad, Option+X on a U.S. layout, ≈ in HTML and \approx in LaTeX.
U+223A. One of five characters used for the idea, with ∝, ∷, ∼ and the keyboard tilde. ∺ in HTML.
U+007E. The keyboard character used for proportionality, as in y ~ x. Unicode cross-references it to ∼, the maths form.
U+003A. In a ratio written A:B the two dots are sometimes the punctuation colon. Unicode's note says ∶ is preferred for that mathematical use. : in HTML.
U+223B. Named after the homothety, a transformation fixed by a centre and a nonzero number k called its ratio. Unicode files it under Relations, right after ∺. ∻ in HTML.
Made of U+0079, U+221D, U+0078 and U+00B2. Proportional to the square. The ² is one character, U+00B2, so it survives where formatting does not.
Made of U+0079, U+221D, U+221A and U+0078. Proportional to the square root, with √, U+221A, in front of the letter.
Made of U+221D, U+0031, U+002F, U+0072 and U+00B2. The inverse-square law: intensity ∝ 1/distance². Put the quantity in front, as in I∝1/r².
Made of U+0078, U+0079, U+003D and U+006B. Inverse proportion as an equation: the product of the two variables is the constant k.
Made of U+006B, U+003D, U+0079, U+002F and U+0078. The constant of proportionality written as a ratio, for x other than 0.
Made of U+0061, U+2236 and U+0062. Two letters around ∶, U+2236, the dedicated ratio character, and not the punctuation colon.
Made of U+221D and U+0338. Unicode has no ready-made character with this meaning. This row adds U+0338, Combining long solidus overlay, the way Unicode makes up ≠ of = and U+0338. How well the stroke sits depends on the font.
Made of U+0043, U+221D and U+0064. The circumference of a circle is directly proportional to its diameter, and the constant is π.
Made of U+0046, U+221D and U+0061. Newton's second law: the net force on an object is proportional to its acceleration, and the constant is the mass.
Made of U+0064, U+221D and U+0074. At a constant speed the distance travelled is directly proportional to the time spent travelling, and the speed is the constant.
U+2243. A tilde over one line. ≃ in HTML and \simeq in LaTeX.
U+2245. A tilde over an equals sign. ≅ in HTML and \cong in LaTeX.
U+223D. Unicode's alias: lazy S. Its note says reversed tilde and lazy S are glyph variants. ∽ in HTML, and \backsim in LaTeX with the amssymb package.
U+2259. Unicode's alias: corresponds to. ≙ in HTML.
U+2258. An equals sign under an arc. It has no Alt code, entity or LaTeX macro in the sources this site uses.
U+1D6FC. The slanted alpha of printed maths, which Unicode makes up of α in an italic font. Added in version 3.1 (2001).
U+0251. A phonetic letter. Unicode's notes: low back unrounded vowel, and the character is sometimes rendered more like a Greek α.
U+237A. The alpha of the APL programming language, in the Miscellaneous Technical block.
U+29DC. An infinity sign with a gap, which Unicode cross-references to ∞. ⧜ in HTML. Added in version 3.2 (2002).
U+223E. Unicode's alias: most positive. ∾ in HTML.
The proportional symbol is ∝, Proportional to, U+221D. The 34 rows add ready-made relations such as y∝x and ∝1/x, the ratio and proportion signs ∶ and ∷, and labelled look-alikes such as α and ∞.
Read the full guide
Which sign says what
y ∝ x means y = kx for some constant k. ∼ is a second way to write it. ∶ and ∷ belong to a is to b as c is to d, written a∶b∷c∶d. ≈ means roughly equal, which is a different claim. α is a Greek letter and ∞ is infinity. After you paste a ready relation, swap in your own letters.
Tips
The ² in y∝x² and ∝1/r² is one character, U+00B2, so the power survives in plain text.
Not proportional to is ∝ plus a combining slash, U+0338. How the stroke sits depends on the font, so check it where you paste it.
Questions and answers
How do I type the proportional symbol on a keyboard?
∝ has no Alt code, no Option key and no Compose sequence in the tables this site checks, so copy it. In a web page write ∝, and in LaTeX write \propto.
What is the directly proportional symbol, and the inversely proportional one?
Both use ∝. y ∝ x is direct proportion: y = kx, so the ratio y/x stays constant. y ∝ 1/x is inverse proportion: y = k/x, so the product xy stays constant. Unicode has no separate character for inverse proportion.
What is the difference between ∝ and α?
∝ is U+221D, Proportional to, a maths relation. α is U+03B1, the Greek small letter alpha. They look alike and are two code points, so a search treats them as different characters. ∞, infinity, is a third.
What is the proportional symbol in HTML and LaTeX?
∝ is the shortest named entity, and ∝ or ∝ is the numeric form. In LaTeX, \propto works in maths mode with no package, and \varpropto needs amssymb. ∷ is ∷ and ∶ is ∶.
Who invented the proportional symbol?
∝ is credited to William Emerson, in 1768. The older proportion sign ∷ is credited to William Oughtred, in 1628.
≈Almost equal toU+2248. Roughly equal, which is a different claim: proportional quantities keep a ratio and need not be near each other. Alt+247 on a number pad, Option+X on a U.S. layout, ≈ in HTML and \approx in LaTeX.
αGreek small letter alphaU+03B1. A letter, not the sign: ∝ is not to be confused with alpha, and Unicode cross-references the two. Alt+224 on a number pad, α in HTML and \alpha in LaTeX.
∞InfinityU+221E. A different sign, for a quantity without bound and not for a relation. Alt+236 on a number pad, Option+5 on a U.S. layout, ∞ in HTML and \infty in LaTeX.
∝1/xInversely proportional to xMade of U+221D, U+0031, U+002F and U+0078. Inverse proportion is written y ∝ 1/x, which means that the product xy stays constant. Put your own letter in front.
∷ProportionU+2237. The as in a is to b as c is to d, written A:B∷C:D. Its table of maths symbols by date credits the sign to William Oughtred, 1628. ∷ in HTML.
Show all 34 proportion signs (29 more)
Start here, continued
∝Proportional toU+221D. y ∝ x says that y is a constant multiple of x. The sign is credited to William Emerson, 1768. ∝ in HTML and \propto in LaTeX. It has no Alt code and no Option key.
∶RatioU+2236. The is to of the same sentence. Unicode's note: preferred to the colon for division or scale in mathematical use. ∶ in HTML.
∼Tilde operatorU+223C. Unicode's first alias: varies with (proportional to). y ∼ x is the second way to write a proportion, except in Japanese texts, where the tilde is kept for intervals. ∼ in HTML and \sim in LaTeX.
y=kxy equals k times xMade of U+0079, U+003D, U+006B and U+0078. The equation behind y ∝ x. k is the constant of proportionality, or constant of variation, and equals the ratio y/x.
y∝xy is proportional to xMade of U+0079, U+221D and U+0078. Direct proportion: there is a constant k with y = kx. Swap in your own letters.
Proportion and ratio signs 4
:ColonU+003A. In a ratio written A:B the two dots are sometimes the punctuation colon. Unicode's note says ∶ is preferred for that mathematical use. : in HTML.
∺Geometric proportionU+223A. One of five characters used for the idea, with ∝, ∷, ∼ and the keyboard tilde. ∺ in HTML.
∻HomotheticU+223B. Named after the homothety, a transformation fixed by a centre and a nonzero number k called its ratio. Unicode files it under Relations, right after ∺. ∻ in HTML.
~TildeU+007E. The keyboard character used for proportionality, as in y ~ x. Unicode cross-references it to ∼, the maths form.
Ready-made relations 10
C∝dCircumference and diameterMade of U+0043, U+221D and U+0064. The circumference of a circle is directly proportional to its diameter, and the constant is π.
d∝tDistance and timeMade of U+0064, U+221D and U+0074. At a constant speed the distance travelled is directly proportional to the time spent travelling, and the speed is the constant.
F∝aForce and accelerationMade of U+0046, U+221D and U+0061. Newton's second law: the net force on an object is proportional to its acceleration, and the constant is the mass.
∝1/r²Inverse-square lawMade of U+221D, U+0031, U+002F, U+0072 and U+00B2. The inverse-square law: intensity ∝ 1/distance². Put the quantity in front, as in I∝1/r².
k=y/xk equals y over xMade of U+006B, U+003D, U+0079, U+002F and U+0078. The constant of proportionality written as a ratio, for x other than 0.
∝̸Not proportional toMade of U+221D and U+0338. Unicode has no ready-made character with this meaning. This row adds U+0338, Combining long solidus overlay, the way Unicode makes up ≠ of = and U+0338. How well the stroke sits depends on the font.
a∶bRatio of a to bMade of U+0061, U+2236 and U+0062. Two letters around ∶, U+2236, the dedicated ratio character, and not the punctuation colon.
xy=kx times y equals kMade of U+0078, U+0079, U+003D and U+006B. Inverse proportion as an equation: the product of the two variables is the constant k.
y∝√xy is proportional to the square root of xMade of U+0079, U+221D, U+221A and U+0078. Proportional to the square root, with √, U+221A, in front of the letter.
y∝x²y is proportional to x squaredMade of U+0079, U+221D, U+0078 and U+00B2. Proportional to the square. The ² is one character, U+00B2, so it survives where formatting does not.
Similar and roughly equal 5
≅Approximately equal toU+2245. A tilde over an equals sign. ≅ in HTML and \cong in LaTeX.
≃Asymptotically equal toU+2243. A tilde over one line. ≃ in HTML and \simeq in LaTeX.
≘Corresponds toU+2258. An equals sign under an arc. It has no Alt code, entity or LaTeX macro in the sources this site uses.
≙EstimatesU+2259. Unicode's alias: corresponds to. ≙ in HTML.
∽Reversed tildeU+223D. Unicode's alias: lazy S. Its note says reversed tilde and lazy S are glyph variants. ∽ in HTML, and \backsim in LaTeX with the amssymb package.
Look-alikes 5
⍺APL functional symbol alphaU+237A. The alpha of the APL programming language, in the Miscellaneous Technical block.
⧜Incomplete infinityU+29DC. An infinity sign with a gap, which Unicode cross-references to ∞. ⧜ in HTML. Added in version 3.2 (2002).
∾Inverted lazy SU+223E. Unicode's alias: most positive. ∾ in HTML.
ɑLatin small letter alphaU+0251. A phonetic letter. Unicode's notes: low back unrounded vowel, and the character is sometimes rendered more like a Greek α.
𝛼Mathematical italic small alphaU+1D6FC. The slanted alpha of printed maths, which Unicode makes up of α in an italic font. Added in version 3.1 (2001).