Mathematical symbol Plus Minus
About this character
The character ± is known as Mathematical symbol Plus Minus and carries the Unicode code point U+00B1, which is 177 in decimal. It belongs to the Latin-1 Supplement block (U+0080–U+00FF), which gathers the accented letters of Western European languages along with the punctuation and symbols inherited from ISO 8859-1.
In memory, ± takes 2 bytes in UTF-8 (0xC2 0xB1) and 1 in UTF-16 (0x00B1). That difference is why badly configured forms or databases garble this character: they assume one byte per character.
How to type ±
| System | What to do |
|---|---|
| Windows | On Windows, hold Alt and type 177 on the numeric keypad. In Word or WordPad, type 00B1 and press Alt + X to turn the code into the character. |
| macOS | On a Mac using the ABC/US layout, ⌥ + ⇧ + = produces this character directly. |
| Linux | On Linux (GTK), type Ctrl + ⇧ + U, 00B1 then press Enter. |
| HTML / Web | In an HTML page, write ±. Use \00B1 in CSS, \u00B1 in JavaScript and \u00B1 in Python. |
| On this site | The simplest route is the Copy button above: the character goes straight to your clipboard, ready to paste anywhere. |
Keyboards that include ±
This character is not on any common physical layout, so the Copy button above is the quickest way to get it into a document.
Codes and encodings
| Property | Value |
|---|---|
| Code point | U+00B1 |
| Unicode block | Latin-1 Supplement (U+0080–U+00FF) |
| Decimal | 177 |
| Hexadecimal | 0x00B1 |
| Octal | 0261 |
| Binary | 10110001 |
| UTF-8 bytes | 0xC2 0xB1 |
| UTF-16 units | 0x00B1 |
| Named HTML entity | ± |
| Decimal HTML entity | ± |
| Hex HTML entity | ± |
| CSS escape | \00B1 |
| JavaScript escape | \u00B1 |
| Python escape | \u00B1 |
| URL encoding | %C2%B1 |
Frequently asked questions
What is the Unicode code for ±?
Its code point is U+00B1, which is 177 in decimal and 0261 in octal. In HTML you can write it as ± or ±.
Why does ± show up as a box or a question mark?
An empty box means the font has no glyph for U+00B1. The character is still in the text: switching to a font that covers the block (Noto, DejaVu or Segoe UI Symbol) makes it appear.
Can I use ± in a filename, a URL or a password?
In a URL it must be encoded as %C2%B1. Modern filesystems accept it, though it is still risky when moving files between systems. For passwords, some forms reject non-ASCII characters outright.