Copy ′, the prime symbol, or ″, the double prime; triple, reversed and ready-made forms follow.
Prime Symbol
′PrimeU+2032Ready to copy
17 prime marks. Tap any value to copy it.
17 prime marks. 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+2032. A short slanted stroke set after a number or a letter: feet, minutes of arc, or in math a derivative or a new value. ′ in HTML, \prime in LaTeX. No Alt code.
U+2033. Two strokes in one character: inches, seconds, a second derivative. ″ in HTML.
U+2034. Three strokes: a third derivative. Unicode also lists it as lines, an old measure of a twelfth of an inch. ‴ in HTML.
The letter x and U+2032, read x prime: a new value made from x, such as the result of a transformation.
The letter y and U+2032, read y prime: the first derivative of y with respect to x.
Both marks with numbers: five feet three inches.
U+2057. Four strokes in one character, for a fourth derivative. It joined Unicode in version 3.2 (2002). ⁗ in HTML.
U+2035. The stroke leaning backward. \backprime in LaTeX needs amssymb; ‵ in HTML.
U+2036. A pair of backward-leaning strokes. It has no HTML name. In LaTeX the unicode-math package names it \backdprime.
U+2037. A trio of backward-leaning strokes, the mirror of ‴.
U+02B9. The prime as a letter and not a punctuation mark. Linguists use it for stress, and for ь when Cyrillic is spelled in Latin script.
U+02BA. Its double, noted for contrastive stress and for the Cyrillic hard sign.
The letter f and U+2032: the derivative of a function f, written f′(x).
The letter f followed by ″: differentiate the function twice.
U+0027. The straight apostrophe from the keyboard, often typed in place of a prime. A different character, and upright where the prime slants.
U+0022. The straight double quote, Shift and the apostrophe key on the U.S. layout: the usual stand-in for ″.
U+00B4. An accent standing alone. It leans the same way but belongs over a vowel. Alt+0180 types it.
The prime symbol is ′, U+2032, a short slanted stroke: feet, minutes, or in math the mark in x′. No key and no Alt code types it. The straight apostrophe on the keyboard is a different character.
Read the full guide
What the prime sign marks
After a number, ′ is feet or minutes of arc and ″ is inches or seconds: 3° 5′ 30″ is 3 degrees, 5 arcminutes and 30 arcseconds. In math, y′ and y″ are the first and second derivatives of y, and x′ can name the result of a transformation. Three prime symbols, ‴, mark a third derivative.
Typing it
No key of the U.S. keyboard carries a prime and neither Alt code table holds one, so there is no keyboard shortcut. A web page writes ′ as ′ and ″ as ″; LaTeX writes \prime.
An apostrophe is often typed in place of a prime; formal typesetting keeps the two apart.
y′ is read y prime.
‴ once stood for the line, a twelfth of an inch.
Questions and answers
What is the prime symbol in math?
A mark for a related version of something. f′(x) is the derivative of f(x), y′ the derivative of y, and x′ a new value made from x. Each added prime means the next higher derivative.
Is the prime symbol on the keyboard?
No. The apostrophe key types U+0027, which is often used in its place. The prime is U+2032, and no key or Alt code produces it, so copy and paste it.
What is the Alt code for the prime symbol?
There is no Alt code for prime marks: neither table holds ′, ″ or ‴. The acute accent ´, which leans the same way, is Alt+0180, but it is an accent and not a prime.
What is the double prime symbol?
″, U+2033, two strokes in one character. It stands for inches, for seconds of arc or of time, and for a second derivative. The straight double quote on the keyboard is the usual stand-in.
Is the prime symbol for minutes or for feet?
Both. 5′ can be five feet or five minutes, and the double prime is then inches or seconds. Unicode records the same pair of meanings: its other names for ′ are minutes and feet.
All 17 prime marks
Start here 6
″Double primeU+2033. Two strokes in one character: inches, seconds, a second derivative. ″ in HTML.
5′3″Feet and inchesBoth marks with numbers: five feet three inches.
′PrimeU+2032. A short slanted stroke set after a number or a letter: feet, minutes of arc, or in math a derivative or a new value. ′ in HTML, \prime in LaTeX. No Alt code.
‴Triple primeU+2034. Three strokes: a third derivative. Unicode also lists it as lines, an old measure of a twelfth of an inch. ‴ in HTML.
x′x primeThe letter x and U+2032, read x prime: a new value made from x, such as the result of a transformation.
y′y primeThe letter y and U+2032, read y prime: the first derivative of y with respect to x.
Primes 1
⁗Quadruple primeU+2057. Four strokes in one character, for a fourth derivative. It joined Unicode in version 3.2 (2002). ⁗ in HTML.
Reversed primes 3
‶Reversed double primeU+2036. A pair of backward-leaning strokes. It has no HTML name. In LaTeX the unicode-math package names it \backdprime.
‵Reversed primeU+2035. The stroke leaning backward. \backprime in LaTeX needs amssymb; ‵ in HTML.
‷Reversed triple primeU+2037. A trio of backward-leaning strokes, the mirror of ‴.
Show all 17 prime marks (7 more)
Primes that are letters 2
ʺModifier letter double primeU+02BA. Its double, noted for contrastive stress and for the Cyrillic hard sign.
ʹModifier letter primeU+02B9. The prime as a letter and not a punctuation mark. Linguists use it for stress, and for ь when Cyrillic is spelled in Latin script.
Ready-made 2
f″f double primeThe letter f followed by ″: differentiate the function twice.
f′f primeThe letter f and U+2032: the derivative of a function f, written f′(x).
Not a prime 3
´Acute accentU+00B4. An accent standing alone. It leans the same way but belongs over a vowel. Alt+0180 types it.
'ApostropheU+0027. The straight apostrophe from the keyboard, often typed in place of a prime. A different character, and upright where the prime slants.
"Quotation markU+0022. The straight double quote, Shift and the apostrophe key on the U.S. layout: the usual stand-in for ″.