Symbol Hub

Partial Derivative Symbol

The partial derivative symbol (∂), the “curly d”, marks differentiation with respect to one variable while the others are held fixed.

Also known as: partial derivative symbol, partial symbol, curly d, del.

Codes

Symbol
UnicodeU+2202
HTML entity (named)∂
HTML entity (decimal)∂
HTML entity (hex)∂
CSS\2202
LaTeX\partial

How to type (Partial Derivative Symbol)

Windows2202, Alt + X

There is no Alt code for ∂. In Word, type 2202 then press Alt + X. Elsewhere, copy ∂ above or use Character Map.

Mac⌥ + D

Press Option + d.

Microsoft Word2202, Alt + X

Type 2202, then press Alt + X to convert it to ∂.

Google Docs

Insert → Special characters, then search “partial”. In an equation, \partial followed by a space also works.

LaTeX\partial

Use \partial in math mode: \frac{\partial f}{\partial x}.

Usage

  • ∂f/∂x is the partial derivative of f with respect to x — the rate of change in the x direction, treating every other variable as a constant.
  • ∂ vs d: use d for an ordinary derivative of a single-variable function (df/dx) and ∂ when the function has several variables. Writing d where ∂ belongs is a real error, not a style choice.
  • ∂ is not a Greek letter, despite the look. It is a stylized cursive d — which is why it is called the curly d. In particular it is not δ (U+03B4, Greek small delta), and not ∆ (U+2206, increment).
  • The gradient collects the partials into a vector: ∇f = (∂f/∂x, ∂f/∂y, ∂f/∂z).

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