Here's a short list of LaTeX and HTML commands for producing the symbols often used when writing up papers or making scientific webpages.

Symbol LaTeX Command HTML Command Result*
Ångström \AA &Aring; Å
Approximately equal to $\approx$ &asymp;
Not equal to $\neq$ &ne;
Percent \% % %
Plus or minus $\pm$ &plusmn; ±
Times $\times$ &times; ×
Scalar multiplied by $\cdot$ &middot; ·
Divided by $\div$ &divide; ÷
Less than $<$ &lt; <
Less than or equal to $\leq$ &le;
Less than or similar to $\lesssim$
Greater than $>$ &gt; >
Greater than or equal to $\geq$ &ge;
Greater than or similar to $\gtrsim$
Square root $\sqrt{...}$ &radic;
Squared $^2$ &sup2; ²
Cubed $^3$ &sup3; ³
Degrees $^\circ$ &deg; °
Micro- $\mu$ &micro; µ
Of the order of (similar to) $\sim$ &sim;
Prime $'$ or $\prime$ &prime;
Double-prime $''$ (two single quote-marks) &Prime;

* As rendered in your browser.

### Notes:

• I want to keep the HTML commands list free from hacks resorting to the use of the symbol font, but this can mean that some of the entity codes listed here will not display properly in older browsers.
• The LaTeX commands assume that you are in normal text mode. The \$'s around a command mean that it has to be used in maths mode, and they will temporarily put you into maths mode if you use them.
• If you can't find the LaTeX symbol(s) that you are after, then I can almost guarantee that you'll find them in the Comprehensive LaTeX Symbol List.