Math & Logic Symbols - Alt Codes & Unicode

These are the mathematical symbols that come up most often outside a formula editor — in emails, chat, documentation, spreadsheets and code comments, where LaTeX is unavailable and an image would be overkill. Each is a real Unicode character rather than an approximation, so ≤ is a single character, not a less-than sign followed by an equals sign.

Using the proper characters matters more than it appears. Writing <= or != is universally understood by programmers but reads as code rather than mathematics in prose, and it breaks screen readers, which announce ≤ as "less than or equal to" but read <= as two separate symbols. It also affects search: a document containing ≠ will not be found by a search for !=. In technical writing intended for humans, the real symbols are worth the small extra effort.

A few of these have close lookalikes that are worth distinguishing. The minus sign − (U+2212) is not the hyphen-minus - on your keyboard; it is wider and aligns with the digits, which is why properly typeset negative numbers look different from hyphenated ones. The multiplication sign × is not the letter x, and the division sign ÷ is not a slash. The prime ′ and double prime ″ mark feet and inches or minutes and seconds of arc, and they are not apostrophes or quotation marks — a common error in coordinates and measurements that makes text hard to parse and search.

The summation ∑ and product ∏ symbols have a subtlety: they are distinct characters from the Greek capital sigma Σ and pi Π, even though they look nearly identical in many fonts. Unicode separates them because they are mathematical operators rather than letters, and using the Greek letters instead breaks mathematical text processing and screen reader output. The same applies to the empty set ∅ versus the Danish and Norwegian letter ø.

On Windows, hold Alt with Num Lock on for the ones with codes: ° is Alt+0176, ± is Alt+0177, × is Alt+0215 and ÷ is Alt+0247. Most of the others have no Alt code and are best copied. On macOS, Option+comma gives ≤, Option+period gives ≥, Option+equals gives ≠, Option+X gives ≈, Option+5 gives ∞, Option+V gives √ and Option+B gives ∫. On Linux, Compose sequences cover several — Compose then < then = gives ≤. In Microsoft Word, typing the Unicode hex value then pressing Alt+X converts it in place, so 2264 then Alt+X gives ≤. For anything heavier than occasional symbols, LaTeX or MathML is the right tool; this table is for the cases where they are not available.