Delta — δ Greek Letter Symbol
δ
Delta — δ / Δ
4th letter of the Greek alphabet · pronounced /ˈdɛltə/
MathematicsPhysicsEngineeringCalculus
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δ
Lowercase delta
Δ
Uppercase Delta
Technical reference
| Unicode (lowercase) | U+03B4 |
| Unicode (uppercase) | U+0394 |
| HTML entity | δ |
| HTML decimal | δ |
| LaTeX | \delta |
| Python / Unicode escape | \u03b4 |
| Alt code (Windows) | Alt + 948 |
Uses in science & engineering
Change / difference (Δ)
Uppercase Delta universally denotes a change or difference between two values. Fundamental in all engineering disciplines.
\(\Delta x = x_2 – x_1\)
Partial derivative
Lowercase delta used in partial differentiation of multivariable functions.
\(\frac{\partial f}{\partial x}\)
Dirac delta function
Generalised function that is zero everywhere except at zero, with integral equal to 1.
\(\int_{-\infty}^{\infty} \delta(x)\, dx = 1\)
Deflection (structural engineering)
Vertical displacement of a beam or structural element under load.
\(\delta_{max} = \frac{5wL^4}{384EI}\)
Kronecker delta
Equals 1 if indices are equal, 0 otherwise. Used in tensor mathematics.
\(\delta_{ij} = \begin{cases}1 & i=j \\ 0 & i\neq j\end{cases}\)
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 “delta”
Microsoft Word
Type 03b4 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