# Kappa

Kappa (uppercase Κ, lowercase κ or cursive ϰ; Greek: κάππα, káppa) is the 10th letter of the Greek alphabet, used to represent the [k] sound in Ancient and Modern Greek. In the system of Greek numerals, has a value of 20. It was derived from the Phoenician letter kaph . Letters that arose from kappa include the Roman K and Cyrillic К.

Greek proper names and placenames containing kappa are often written in English with "c" due to the Romans' transliterations into the Latin alphabet: Constantinople, Corinth, Crete. All formal modern romanizations of Greek now use the letter "k", however.

The cursive form ϰ is generally a simple font variant of lower-case kappa, but it is encoded separately in Unicode for occasions where it is used as a separate symbol in math and science. In mathematics, the kappa curve is named after this letter; the tangents of this curve were first calculated by Isaac Barrow in the 17th century.

## Symbol

### Lowercase (κ)

Mathematics and statistics
Physics
Engineering
• In structural engineering, κ is the ratio of the smaller factored moment to the larger factored moment and is used to calculate the critical elastic moment of an unbraced steel member.
• In electrical engineering, κ is the multiplication factor, a function of the R/X ratio of the equivalent power system network, which is used in calculating the peak short-circuit current of a system fault. κ is also used to notate conductivity, the reciprocal of resistivity, rho.
Biology and biomedical science
Psychology and psychiatry
Economics

### Uppercase (Κ)

History
Mathematics and statistics
Chemistry

## Character encodings

CharacterΚκϰ
Unicode nameGREEK CAPITAL LETTER KAPPAGREEK SMALL LETTER KAPPAGREEK KAPPA SYMBOLCOPTIC CAPITAL LETTER KAPACOPTIC SMALL LETTER KAPA
Encodingsdecimalhexdecimalhexdecimalhexdecimalhexdecimalhex
Unicode922U+039A954U+03BA1008U+03F011412U+2C9411413U+2C95
UTF-8206 154CE 9A206 186CE BA207 176CF B0226 178 148E2 B2 94226 178 149E2 B2 95
Numeric character reference&#922;&#x39A;&#954;&#x3BA;&#1008;&#x3F0;&#11412;&#x2C94;&#11413;&#x2C95;
Named character reference&Kappa;&kappa;
DOS Greek13789161A1
DOS Greek-2181B5228E4
Windows 1253202CA234EA
TeX\kappa
• Mathematical Kappa
Character𝚱𝛋𝛞𝛫𝜅
Unicode nameMATHEMATICAL BOLD
CAPITAL KAPPA
MATHEMATICAL BOLD
SMALL KAPPA
MATHEMATICAL BOLD
KAPPA SYMBOL
MATHEMATICAL ITALIC
CAPITAL KAPPA
MATHEMATICAL ITALIC
SMALL KAPPA
Encodingsdecimalhexdecimalhexdecimalhexdecimalhexdecimalhex
Unicode120497U+1D6B1120523U+1D6CB120542U+1D6DE120555U+1D6EB120581U+1D705
UTF-8240 157 154 177F0 9D 9A B1240 157 155 139F0 9D 9B 8B240 157 155 158F0 9D 9B 9E240 157 155 171F0 9D 9B AB240 157 156 133F0 9D 9C 85
UTF-1655349 57009D835 DEB155349 57035D835 DECB55349 57054D835 DEDE55349 57067D835 DEEB55349 57093D835 DF05
Numeric character reference&#120497;&#x1D6B1;&#120523;&#x1D6CB;&#120542;&#x1D6DE;&#120555;&#x1D6EB;&#120581;&#x1D705;
Character𝜘𝜥𝜿𝝒𝝟
Unicode nameMATHEMATICAL ITALIC
KAPPA SYMBOL
MATHEMATICAL BOLD ITALIC
CAPITAL KAPPA
MATHEMATICAL BOLD ITALIC
SMALL KAPPA
MATHEMATICAL BOLD ITALIC
KAPPA SYMBOL
MATHEMATICAL SANS-SERIF
BOLD CAPITAL KAPPA
Encodingsdecimalhexdecimalhexdecimalhexdecimalhexdecimalhex
Unicode120600U+1D718120613U+1D725120639U+1D73F120658U+1D752120671U+1D75F
UTF-8240 157 156 152F0 9D 9C 98240 157 156 165F0 9D 9C A5240 157 156 191F0 9D 9C BF240 157 157 146F0 9D 9D 92240 157 157 159F0 9D 9D 9F
UTF-1655349 57112D835 DF1855349 57125D835 DF2555349 57151D835 DF3F55349 57170D835 DF5255349 57183D835 DF5F
Numeric character reference&#120600;&#x1D718;&#120613;&#x1D725;&#120639;&#x1D73F;&#120658;&#x1D752;&#120671;&#x1D75F;
Character𝝹𝞌𝞙𝞳𝟆
Unicode nameMATHEMATICAL SANS-SERIF
BOLD SMALL KAPPA
MATHEMATICAL SANS-SERIF
BOLD KAPPA SYMBOL
MATHEMATICAL SANS-SERIF
BOLD ITALIC CAPITAL KAPPA
MATHEMATICAL SANS-SERIF
BOLD ITALIC SMALL KAPPA
MATHEMATICAL SANS-SERIF
BOLD ITALIC KAPPA SYMBOL
Encodingsdecimalhexdecimalhexdecimalhexdecimalhexdecimalhex
Unicode120697U+1D779120716U+1D78C120729U+1D799120755U+1D7B3120774U+1D7C6
UTF-8240 157 157 185F0 9D 9D B9240 157 158 140F0 9D 9E 8C240 157 158 153F0 9D 9E 99240 157 158 179F0 9D 9E B3240 157 159 134F0 9D 9F 86
UTF-1655349 57209D835 DF7955349 57228D835 DF8C55349 57241D835 DF9955349 57267D835 DFB355349 57286D835 DFC6
Numeric character reference&#120697;&#x1D779;&#120716;&#x1D78C;&#120729;&#x1D799;&#120755;&#x1D7B3;&#120774;&#x1D7C6;

These characters are used only as mathematical symbols. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style.