Mathematical formulas can be written in HTML without installing special fonts, MathML, or inserting images. This article shows how this can be done.

SymbolEntityDescription
¬¬not sign
¯¯macron, overline
°°degree sign
±±plus-minus sign
µµmicro sign
··middle dot, centered period
××multiplication sign
÷÷division sign
ƒƒf with hook, script f
–monospaced hyphen
−−minus sign
––en dash
——em dash
††dagger
‡‡double dagger
••bullet
……ellipsis
′′prime, minute
″″double prime, second
⁄⁄fraction slash
ΩΩohm sign
←←leftwards arrow
↑↑upwards arrow
→→rightwards arrow
↓↓downwards arrow
↔↔left right arrow
↕↕up down arrow
∂∂partial differential
∆∆increment, difference
∏∏product
∑∑summation, sum
√√square root, radical
∞∞infinity
∩∩intersection
∫∫integral
⌠⌠top half integral
⌡⌡bottom half integral
≈≈almost equal to, approximately equal to
≠≠not equal to
≡≡identical to
≤≤less than or equal to
≥≥greater than or equal to

√(a2 + b2)

liman
n→∞

∞ ∑ an n=0

∞
∑
n = 0
an

{ sum from n = 0 to infinity } a_n


∆u  =  Δu  = n
∑
i = 1
∂2u/∂xi2

Laplacian of u = Delta u = { sum from i = 1 to n } d^2u / dx_i^2


∞
∏
n = 0
an

{ product from n = 0 to infinity } a_n


  b
∫
a  
f(x)dx

{ integral from a to b } f(x) dx


 +∞
∫
−∞ 
exp(−x2)dx =  √π

{ integral from -infinity to +infinity } exp(-x^2) dx = square root of pi