How to type Prime
To type Prime (′), press Alt + 8242 on Windows, holding Alt while typing the digits on the numeric keypad, or write ′ in HTML. On any system you can copy it from this page, or enter its codepoint U+2032 directly: Ctrl+Shift+U then 2032 on Linux, or 2032 then Alt+X in Microsoft Word.
Prime
- Copy it
- Unicode
- U+2032
- Windows
- Alt + 8242 needs regedit
| Where | Shortcut | How |
|---|---|---|
| Windows | Alt + 8242 | Above 255, so Windows will not accept it as typed. Copy the character instead. |
| Mac | N/A | Press the keys together. |
| HTML | ′ | Paste this into HTML source. |
| Unicode | U+2032 | PRIME |
Symbols related to Prime
The Unicode code chart points from ′ to ', and Unicode's confusables table, the one registrars use against spoofed domains, lists `, ‘ and ’ as close enough to be mistaken for it, and the rest are filed under prime in CLDR, the keyword list Unicode publishes alongside the names.
Other math symbols
′ lives in the General Punctuation block (U+2000-U+206F), dashes, quotation marks, spaces and reference marks used across languages. Within Unicode it is classified as Po, a punctuation mark. Its bidirectional class makes it a European number terminator, so it sits beside a number without breaking its direction.
What Prime is used for
In mathematical notation ′ is an ordinary symbol: it carries no special spacing and sits in an expression the way a letter does, standing for a thing rather than doing something to the things around it. That is the classification unicode-math gives it, and it is what decides how the symbol is set: $\prime$ in LaTeX, in maths mode rather than in a sentence.
What ′ gets confused with
′ has lookalikes that are a different character underneath. Search, sorting and anything that compares strings can tell them apart even where a reader cannot.
’ (U+2019) is the right single quote, which is what a word processor substitutes when you type an apostrophe. That substitution is why so many measurements are written with the wrong character.
' (U+0027) is the ASCII apostrophe.
What Unicode says about Prime
The standard recognises ′ under another name as well: minutes, feet. That is a formal alias, not a nickname, which is why it turns up in other people's documentation for the same codepoint.
The code chart points from ′ to Apostrophe, acute accent (U+00B4) and modifier letter prime (U+02B9). These are the characters the standard thinks you might have meant instead, which makes them the ones worth checking when Prime looks nearly right but not quite.
How Prime behaves in software
′ is East Asian Ambiguous: one column in a Western locale and two in a CJK one. That is why a table that lines up on your machine can break on somebody else's, with no change to the text at all. It carries no direction of its own, so in a line that mixes English with Arabic or Hebrew it takes the direction of the text around it rather than forcing one.
What people ask about Prime
What is f prime of x mean?
′ is PRIME, encoded at U+2032. It is distinct from apostrophe (U+0027) and acute accent (U+00B4), which the chart lists beside it precisely because they are confused for one another.
Every way to write Prime
| Form | Value |
|---|---|
| Codepoint | U+2032 |
| Decimal | 8242 |
| UTF-8 bytes | E2 80 B2 |
| UTF-16 bytes | 20 32 |
| HTML entity | ′ |
| HTML numeric | ′ or ′ |
| CSS | \2032 |
| JavaScript | \u2032 |
| Python | \u2032 |
| URL-encoded | %E2%80%B2 |
| LaTeX, in maths mode | $\prime$ |
| SVG | 2032.svg · (SIL Open Font License) |
If ′ arrives as ′
One character has become three, which is what a three-byte UTF-8 sequence looks like when each byte is read separately: E2 80 B2 read as Windows-1252 gives exactly ′. The text is intact and the damage is in the reading, so setting the reader to UTF-8 restores it and retyping does not. A rectangle instead of the mojibake means the opposite: the encoding is right and the font has no glyph at U+2032, which for a character this far outside Latin-1 is common in older office fonts.