Kappa — κ Greek Letter Symbol
κ
Kappa — κ / Κ
10th letter of the Greek alphabet · pronounced /ˈkæpə/
PhysicsEngineeringStatisticsOptics
Copy symbol
κ
Lowercase kappa
Κ
Uppercase Kappa
Technical reference
| Unicode (lowercase) | U+03BA |
| Unicode (uppercase) | U+039A |
| HTML entity | κ |
| HTML decimal | κ |
| LaTeX | \kappa |
| Python / Unicode escape | \u03ba |
| Alt code (Windows) | Alt + 954 |
Uses in science & engineering
Thermal conductivity
Rate at which a material conducts heat. Fundamental in heat transfer calculations.
\(q = -\kappa \nabla T\)
Dielectric constant
Ratio of the permittivity of a material to that of a vacuum (relative permittivity).
\(\kappa = \frac{\varepsilon}{\varepsilon_0}\)
Curvature
Measure of how sharply a curve bends at a given point.
\(\kappa = \frac{|y”|}{(1+y’^2)^{3/2}}\)
Cohen’s kappa (statistics)
Measure of inter-rater agreement for categorical items, correcting for chance.
\(\kappa = \frac{p_o – p_e}{1 – p_e}\)
Compressibility (fluid mechanics)
Bulk modulus reciprocal; how much a fluid compresses under pressure.
\(\kappa = -\frac{1}{V}\frac{dV}{dP}\)
Related symbols
How to insert in applications
Windows
Best option: copy from this page.
Or press Win + . to open emoji & symbols panel.
Alt codes work only in Word/Notepad with NumLock on and English layout — not in browsers.
Or press Win + . to open emoji & symbols panel.
Alt codes work only in Word/Notepad with NumLock on and English layout — not in browsers.
macOS
Press ⌃⌘Space → Character Viewer → search “kappa”
Microsoft Word
Type 03ba then press Alt+X
Google Docs
Insert → Special characters → search by name
Excel
Insert → Symbol → Subset: Greek → select symbol
LaTeX
Use in math mode: $ … $
Python
Use Unicode escape or chr()
HTML / CSS
Use HTML entity or decimal code