Standard Deviation Symbol Copy Paste

Copy σ for a standard deviation, or take the sum symbol ∑, capital Σ or a string such as σ².

σGreek small letter sigmaU+03C3Ready to copy

64 sigma characters and formulas. Tap any value to copy it.

64 sigma characters and formulas. 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+03C3. The symbol for the standard deviation of a population, and the eighteenth letter of the Greek alphabet. Alt+229 on a number pad types it. σ in HTML and \sigma in LaTeX.
	U+2211. The summation sign, Unicode's alias for it: an enlarged capital sigma that tells you to add up every term. Option+W types it. ∑ in HTML and \sum in LaTeX.
	U+03A3. The capital letter, for Greek words and for names such as the covariance matrix. Alt+228 on a number pad types it. For a sum, the operator U+2211 is the matching character. Σ in HTML and \Sigma in LaTeX.
	U+03C2. The form a small sigma takes at the end of a Greek word: the name Ὀδυσσεύς has two σ in the middle and ς last. &sigmaf; in HTML and \varsigma in LaTeX.
	U+1D70E. The slanted sigma of a printed formula. Unicode defines it as U+03C3 in an italic font. It has no HTML name of its own.
	U+1D6BA. Upright bold capital: U+03A3 in a bold font, by Unicode's definition. Some books set the covariance matrix in a changed form like this to keep it apart from the summation sign.
	Made of U+03C3 and U+00B2. Sigma squared, made with the superscript two, U+00B2. The variance is the square of the standard deviation.
	Made of U+03C3 and U+2093. Sigma with a subscript x, U+2093, which names the variable the deviation belongs to.
	Made of U+03C3 and U+0302. Sigma with a combining circumflex, U+0302. A hat marks an estimate, so this is an estimated standard deviation.
	Made of U+0033 and U+03C3. Three standard deviations. In a normal distribution about 99.7% of values lie within three of the mean.
	Made of U+2211 and U+0078. The summation sign, U+2211, then x: every value of x added together. It is the top line of a mean.
	Made of U+2211, U+0078 and U+00B2. Each value of x squared, then the squares added. The two is the superscript U+00B2.
	Made of U+0031 and U+03C3. One standard deviation. In a normal distribution about 68.3% of values lie within one of the mean.
	Made of U+0032 and U+03C3. Two standard deviations. About 95.4% of a normal distribution lies within two of the mean.
	Made of U+0035 and U+03C3. The level particle physics asks for before it declares a discovery: about one chance in 3.5 million that a random fluctuation gave the result.
	Made of U+03BC, U+00B1, U+0033 and U+03C3. Three standard deviations either side of the mean μ, the range that holds about 99.7% of a normal distribution. The middle sign is U+00B1.
	Made of U+03C3, U+002F, U+221A and U+006E. The standard deviation divided by the square root of the sample size: sigma, a slash, the root sign U+221A, then n.
	U+2140. The summation sign with doubled strokes. Unicode defines it as U+2211 in a double-struck font. Added in Unicode version 3.2 (2002).
	U+23B2. The top half of a tall summation sign. It goes on one line with U+23B3 on the line below, to make a sign two lines high.
	U+23B3. The bottom half of the tall sign, to sit under U+23B2.
	U+2A0A. Filed under Summations and integrals, and cross-referenced to U+2211. Added in Unicode version 3.2 (2002).
	U+2A0B. A summation sign with an integral sign through it, filed under Summations and integrals.
	U+1EEF0. Unicode's note says it is used in Arabic mathematics to denote summation, and that it stretches at the tatweel. Added in Unicode version 6.1 (2012).
	Made of U+2211, U+0078 and U+0079. Each x multiplied by its y, then the products added together.
	Made of U+2211, U+0066 and U+0078. Each value multiplied by its frequency, then added: the top line of a mean taken from a frequency table.
	Made of U+2211, U+0078 and U+1D62. The summation sign, x, then a subscript i, U+1D62. The i is the index of summation, which goes up by one for each term.
	U+1D6D4. Upright bold. One of five maths styles of the small letter, all added in Unicode version 3.1 (2001).
	U+1D748. Bold and slanted: U+03C3 in a bold italic font.
	U+1D782. Bold with no serifs. Unicode has sans-serif Greek in bold and bold italic only.
	U+1D7BC. Bold, slanted and without serifs.
	Made of U+03C3, U+0028, U+006E and U+0029. The sigma function of number theory: every divisor of n added up, so σ(6) is 1 + 2 + 3 + 6, which is 12.
	U+1D6F4. Slanted capital: U+03A3 in an italic font.
	U+1D72E. Bold and slanted capital.
	U+1D768. Bold capital with no serifs.
	U+1D7A2. Bold, slanted capital with no serifs.
	Made of U+03A3 and U+207A. Capital sigma with a superscript plus, U+207A: a particle made of two up quarks and a strange quark.
	Made of U+03A3 and U+2070. Capital sigma with a superscript zero, U+2070: the neutral member of the family, made of an up, a down and a strange quark.
	Made of U+03A3 and U+207B. Capital sigma with a superscript minus, U+207B: two down quarks and a strange quark.
	U+1D6D3. Final sigma in upright bold. Unicode defines it as U+03C2 in a bold font.
	U+1D70D. Final sigma in italic, the shape \varsigma prints in a formula.
	U+1D747. Final sigma in bold italic.
	U+1D781. Final sigma in sans-serif bold.
	U+1D7BB. Final sigma in sans-serif bold italic.
	U+03F2. Sigma drawn as a crescent, like a Latin c. The shape grew out of Hellenistic handwriting and was the standard sigma of late antiquity and the Middle Ages. Greek church lettering still uses it.
	U+03F9. The capital crescent sigma, as in the Christogram ΙϹ ΧϹ. Unicode defines it as a form of U+03A3. Added in Unicode version 4.0 (2003).
	U+03FD. Unicode's alias is antisigma. Ancient editors set it beside a line that was out of place. Added in Unicode version 4.1 (2005).
	U+03FE. Unicode's alias is sigma periestigmenon, the dotted sigma. Aristarchus of Samothrace used it to mark a line that stood in the wrong position.
	U+03FF. Unicode's alias is antisigma periestigmenon, the dotted antisigma, another of the ancient editors' marks.
	U+037B. The small letter of the antisigma. Unicode files it under Lowercase of editorial symbols. Added in Unicode version 5.0 (2006).
	U+037C. The small dotted lunate sigma.
	U+037D. The small dotted antisigma.
	U+03FA. San, an archaic Greek letter for the s sound. Herodotus wrote that the Dorians called the letter san where the Ionians said sigma. Added in Unicode version 4.0 (2003).
	U+03FB. The small letter of the san pair.
	U+03DA. Not a sigma: Unicode's notes call it, in origin, a cursive digamma, used as the numeral six. The name stigma first belonged to a medieval ligature of sigma and tau that looked much the same.
	U+03DB. The small stigma. Unicode cross-references it to the final sigma, the shape it is mistaken for.
	U+2CA4. Sima, the Coptic s, which comes from the lunate form of sigma. Added in Unicode version 4.1 (2005).
	U+2CA5. The small letter of the Coptic pair.
	U+0421. Es, the Cyrillic s. It derives from the lunate sigma, which is why it looks like a Latin C. &Scy; in HTML.
	U+0441. Small es, &scy; in HTML.
	U+01A9. A Latin letter of African alphabets, the capital of ʃ. Unicode cross-references it to the capital sigma and to the summation sign, the two it is mistaken for.
	U+2183. A backwards C from Roman numerals. Unicode cross-references it to the antisigma, U+03FD.
	U+2184. The small backwards c, cross-referenced to the small antisigma, U+037B. Added in Unicode version 5.0 (2006).
	U+A73E. A backwards C with a dot, cross-referenced to the dotted antisigma, U+03FF. Added in Unicode version 5.1 (2008).
	U+A73F. The small letter of the pair, cross-referenced to U+037D.

Next step σ is Alt+229: the whole table of Alt codes Your own words in serif bold and italic

How it works

σ is the standard deviation symbol: Greek small letter sigma, U+03C3. The summation symbol ∑, U+2211, is the second of 64 rows, ahead of the capital Σ, final ς and strings such as σ², 3σ, σ/√n and ∑x².

Read the full guide

∑ for a sum, Σ for a letter

Unicode keeps two characters. ∑, U+2211, is the summation sign, an enlarged capital sigma used as an operator. Σ, U+03A3, is the capital letter of Greek words. Each cross-references the other in Unicode's notes. Alt+228 types the letter, while Option+W and \sum in LaTeX give the operator.

Tips

σ belongs to a whole population. For a sample, statistics writes a plain s, so the two variances are σ² and s².
Particle physics waits for 5σ before it declares a discovery: about one chance in 3.5 million that a random fluctuation gave the result.
At the end of a Greek word, small sigma takes the final form ς, as in Ὀδυσσεύς.

Questions and answers

How do I type the standard deviation symbol on a keyboard?

On Windows, hold Alt and type 229 on the number pad for σ, or 228 for the capital Σ. In Word, type 03C3, then Alt and X. On a Mac with the U.S. layout, Option and W types ∑, and σ has no Option key.

What is the difference between σ and s?

σ is the standard deviation of a population or a probability distribution. s is the corrected sample standard deviation, worked out with N − 1 in place of N, which is called Bessel's correction.

Which summation symbol should I copy and paste, ∑ or Σ?

For a sum, copy ∑, U+2211. Unicode names it N-ary summation and gives summation sign as its alias. Σ, U+03A3, is the Greek capital letter. They look alike and are two code points, so a formula should hold the first.

What is the HTML code for sigma and the sum symbol?

σ is σ, Σ is the capital, &sigmaf; is the final ς and ∑ is the summation sign ∑. As numbers, σ is σ or σ, and ∑ is ∑ or ∑. Case matters: Σ is not σ.

All 64 sigma characters and formulas

Start here 12

Greek capital letter sigma U+03A3. The capital letter, for Greek words and for names such as the covariance matrix. Alt+228 on a number pad types it. For a sum, the operator U+2211 is the matching character. Σ in HTML and \Sigma in LaTeX.
Greek small letter final sigma U+03C2. The form a small sigma takes at the end of a Greek word: the name Ὀδυσσεύς has two σ in the middle and ς last. &sigmaf; in HTML and \varsigma in LaTeX.
Greek small letter sigma U+03C3. The symbol for the standard deviation of a population, and the eighteenth letter of the Greek alphabet. Alt+229 on a number pad types it. σ in HTML and \sigma in LaTeX.
Mathematical bold capital sigma U+1D6BA. Upright bold capital: U+03A3 in a bold font, by Unicode's definition. Some books set the covariance matrix in a changed form like this to keep it apart from the summation sign.
Mathematical italic small sigma U+1D70E. The slanted sigma of a printed formula. Unicode defines it as U+03C3 in an italic font. It has no HTML name of its own.

Show all 64 sigma characters and formulas (59 more)

Start here, continued

N-ary summation U+2211. The summation sign, Unicode's alias for it: an enlarged capital sigma that tells you to add up every term. Option+W types it. ∑ in HTML and \sum in LaTeX.
Sigma hat Made of U+03C3 and U+0302. Sigma with a combining circumflex, U+0302. A hat marks an estimate, so this is an estimated standard deviation.
Standard deviation of x Made of U+03C3 and U+2093. Sigma with a subscript x, U+2093, which names the variable the deviation belongs to.
Sum of x Made of U+2211 and U+0078. The summation sign, U+2211, then x: every value of x added together. It is the top line of a mean.
Sum of x squared Made of U+2211, U+0078 and U+00B2. Each value of x squared, then the squares added. The two is the superscript U+00B2.
Three sigma Made of U+0033 and U+03C3. Three standard deviations. In a normal distribution about 99.7% of values lie within three of the mean.
Variance Made of U+03C3 and U+00B2. Sigma squared, made with the superscript two, U+00B2. The variance is the square of the standard deviation.

Standard deviation 5

Five sigma Made of U+0035 and U+03C3. The level particle physics asks for before it declares a discovery: about one chance in 3.5 million that a random fluctuation gave the result.
Mean plus or minus three sigma Made of U+03BC, U+00B1, U+0033 and U+03C3. Three standard deviations either side of the mean μ, the range that holds about 99.7% of a normal distribution. The middle sign is U+00B1.
One sigma Made of U+0031 and U+03C3. One standard deviation. In a normal distribution about 68.3% of values lie within one of the mean.
Standard error of the mean Made of U+03C3, U+002F, U+221A and U+006E. The standard deviation divided by the square root of the sample size: sigma, a slash, the root sign U+221A, then n.
Two sigma Made of U+0032 and U+03C3. Two standard deviations. About 95.4% of a normal distribution lies within two of the mean.

Summation signs 9

Arabic mathematical operator meem with hah with tatweel U+1EEF0. Unicode's note says it is used in Arabic mathematics to denote summation, and that it stretches at the tatweel. Added in Unicode version 6.1 (2012).
Double-struck n-ary summation U+2140. The summation sign with doubled strokes. Unicode defines it as U+2211 in a double-struck font. Added in Unicode version 3.2 (2002).
Modulo two sum U+2A0A. Filed under Summations and integrals, and cross-referenced to U+2211. Added in Unicode version 3.2 (2002).
Sum of f times x Made of U+2211, U+0066 and U+0078. Each value multiplied by its frequency, then added: the top line of a mean taken from a frequency table.
Sum of x sub i Made of U+2211, U+0078 and U+1D62. The summation sign, x, then a subscript i, U+1D62. The i is the index of summation, which goes up by one for each term.
Sum of x times y Made of U+2211, U+0078 and U+0079. Each x multiplied by its y, then the products added together.
Summation bottom U+23B3. The bottom half of the tall sign, to sit under U+23B2.
Summation top U+23B2. The top half of a tall summation sign. It goes on one line with U+23B3 on the line below, to make a sign two lines high.
Summation with integral U+2A0B. A summation sign with an integral sign through it, filed under Summations and integrals.

Small sigma σ 5

Mathematical bold italic small sigma U+1D748. Bold and slanted: U+03C3 in a bold italic font.
Mathematical bold small sigma U+1D6D4. Upright bold. One of five maths styles of the small letter, all added in Unicode version 3.1 (2001).
Mathematical sans-serif bold italic small sigma U+1D7BC. Bold, slanted and without serifs.
Mathematical sans-serif bold small sigma U+1D782. Bold with no serifs. Unicode has sans-serif Greek in bold and bold italic only.
Sum of divisors of n Made of U+03C3, U+0028, U+006E and U+0029. The sigma function of number theory: every divisor of n added up, so σ(6) is 1 + 2 + 3 + 6, which is 12.

Capital sigma Σ 7

Mathematical bold italic capital sigma U+1D72E. Bold and slanted capital.
Mathematical italic capital sigma U+1D6F4. Slanted capital: U+03A3 in an italic font.
Mathematical sans-serif bold capital sigma U+1D768. Bold capital with no serifs.
Mathematical sans-serif bold italic capital sigma U+1D7A2. Bold, slanted capital with no serifs.
Sigma minus baryon Made of U+03A3 and U+207B. Capital sigma with a superscript minus, U+207B: two down quarks and a strange quark.
Sigma plus baryon Made of U+03A3 and U+207A. Capital sigma with a superscript plus, U+207A: a particle made of two up quarks and a strange quark.
Sigma zero baryon Made of U+03A3 and U+2070. Capital sigma with a superscript zero, U+2070: the neutral member of the family, made of an up, a down and a strange quark.

Final sigma ς 5

Mathematical bold italic small final sigma U+1D747. Final sigma in bold italic.
Mathematical bold small final sigma U+1D6D3. Final sigma in upright bold. Unicode defines it as U+03C2 in a bold font.
Mathematical italic small final sigma U+1D70D. Final sigma in italic, the shape \varsigma prints in a formula.
Mathematical sans-serif bold italic small final sigma U+1D7BB. Final sigma in sans-serif bold italic.
Mathematical sans-serif bold small final sigma U+1D781. Final sigma in sans-serif bold.

Lunate sigma ϲ 8

Greek capital dotted lunate sigma symbol U+03FE. Unicode's alias is sigma periestigmenon, the dotted sigma. Aristarchus of Samothrace used it to mark a line that stood in the wrong position.
Greek capital lunate sigma symbol U+03F9. The capital crescent sigma, as in the Christogram ΙϹ ΧϹ. Unicode defines it as a form of U+03A3. Added in Unicode version 4.0 (2003).
Greek capital reversed dotted lunate sigma symbol U+03FF. Unicode's alias is antisigma periestigmenon, the dotted antisigma, another of the ancient editors' marks.
Greek capital reversed lunate sigma symbol U+03FD. Unicode's alias is antisigma. Ancient editors set it beside a line that was out of place. Added in Unicode version 4.1 (2005).
Greek lunate sigma symbol U+03F2. Sigma drawn as a crescent, like a Latin c. The shape grew out of Hellenistic handwriting and was the standard sigma of late antiquity and the Middle Ages. Greek church lettering still uses it.
Greek small dotted lunate sigma symbol U+037C. The small dotted lunate sigma.
Greek small reversed dotted lunate sigma symbol U+037D. The small dotted antisigma.
Greek small reversed lunate sigma symbol U+037B. The small letter of the antisigma. Unicode files it under Lowercase of editorial symbols. Added in Unicode version 5.0 (2006).

Relatives in other alphabets 8

Coptic capital letter sima U+2CA4. Sima, the Coptic s, which comes from the lunate form of sigma. Added in Unicode version 4.1 (2005).
Coptic small letter sima U+2CA5. The small letter of the Coptic pair.
Cyrillic capital letter es U+0421. Es, the Cyrillic s. It derives from the lunate sigma, which is why it looks like a Latin C. &Scy; in HTML.
Cyrillic small letter es U+0441. Small es, &scy; in HTML.
Greek capital letter san U+03FA. San, an archaic Greek letter for the s sound. Herodotus wrote that the Dorians called the letter san where the Ionians said sigma. Added in Unicode version 4.0 (2003).
Greek letter stigma U+03DA. Not a sigma: Unicode's notes call it, in origin, a cursive digamma, used as the numeral six. The name stigma first belonged to a medieval ligature of sigma and tau that looked much the same.
Greek small letter san U+03FB. The small letter of the san pair.
Greek small letter stigma U+03DB. The small stigma. Unicode cross-references it to the final sigma, the shape it is mistaken for.

Look-alikes that are not sigma 5

Latin capital letter esh U+01A9. A Latin letter of African alphabets, the capital of ʃ. Unicode cross-references it to the capital sigma and to the summation sign, the two it is mistaken for.
Latin capital letter reversed C with dot U+A73E. A backwards C with a dot, cross-referenced to the dotted antisigma, U+03FF. Added in Unicode version 5.1 (2008).
Latin small letter reversed c U+2184. The small backwards c, cross-referenced to the small antisigma, U+037B. Added in Unicode version 5.0 (2006).
Latin small letter reversed c with dot U+A73F. The small letter of the pair, cross-referenced to U+037D.
Roman numeral reversed one hundred U+2183. A backwards C from Roman numerals. Unicode cross-references it to the antisigma, U+03FD.

How this list was compiled: Names, and the code points they belong to, are checked against UnicodeData.txt, version 18.0.0 (https://www.unicode.org/Public/18.0.0/ucd/UnicodeData.txt, checked 2026-09-20), and printed in sentence case. Notes that say Unicode's note, Unicode's alias, Unicode files it or cross-references quote the headings, aliases, notes and cross-references of NamesList.txt of the same version (https://www.unicode.org/Public/18.0.0/ucd/NamesList.txt); the version a character was added in is from DerivedAge.txt (https://www.unicode.org/Public/18.0.0/ucd/DerivedAge.txt), block names are from Blocks.txt, the Emoji property and the text style and emoji style sequences are from emoji-data.txt and emoji-variation-sequences.txt of the same version, and the years are from https://www.unicode.org/history/publicationdates.html. Alt codes are from the code page 437 table (https://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/PC/CP437.TXT), the PC graphics table for codes 1 to 31 (https://www.unicode.org/Public/MAPPINGS/VENDORS/MISC/IBMGRAPH.TXT) and the code page 1252 table (https://www.unicode.org/Public/MAPPINGS/VENDORS/MICSFT/WINDOWS/CP1252.TXT). Option keys were read from a U.S. keyboard layout; other layouts differ. HTML entity names are from https://html.spec.whatwg.org/entities.json, the HTML 4 name first where there is one, else the shortest. LaTeX macros are listed only when LaTeX's own fontdef.dtx or ltoutenc.dtx (https://github.com/latex3/latex2e/tree/develop/base) or the amssymb and amsfonts sources (https://mirrors.ctan.org/fonts/amsfonts/source/) define them, matched to a code point through unicode-math-table.tex (https://github.com/latex3/unicode-math). Uses and history were checked on 2026-09-20 against https://en.wikipedia.org/wiki/Sigma (eighteenth letter, final sigma and the name Odysseus, the lunate sigma and the editorial signs, san and Herodotus, Cyrillic es and Coptic sima from the lunate form, the covariance matrix, the sum-of-divisors function), https://en.wikipedia.org/wiki/Standard_deviation (sigma for a population, variance as sigma squared, 68.3, 95.4 and 99.7 percent, five sigma and one chance in 3.5 million, sigma hat, the standard deviation of the mean), https://en.wikipedia.org/wiki/Summation (an enlarged capital sigma, the index of summation) and https://en.wikipedia.org/wiki/Sigma_baryon (uus, uds and dds). Made rows for sums use the operator U+2211 and never the letter U+03A3. Start here is this site's own pick. Licence: own work (facts from the Unicode Character Database, Unicode License v3, and from Wikipedia, CC BY-SA 4.0, restated in our own words; aliases and notes marked as Unicode's are quoted from NamesList.txt, Copyright © 1991-2026 Unicode, Inc., https://www.unicode.org/license.txt)