Mathematical symbol Union
About this character
The character ∪ carries the official Unicode name “Mathematical symbol Union” and the code point U+222A, which is 8746 in decimal. It belongs to the Mathematical Operators block (U+2200–U+22FF), which gathers the operators, quantifiers and relations of algebra, logic and set theory.
In memory, ∪ takes 3 bytes in UTF-8 (0xE2 0x88 0xAA) and 1 in UTF-16 (0x222A). 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 | In Word or WordPad, type 222A and press Alt + X to turn the code into the character. |
| macOS | On a Mac, open the Character Viewer with Ctrl + ⌘ + Space and search for “Mathematical symbol Union”. |
| Linux | On Linux (GTK), type Ctrl + ⇧ + U, 222A then press Enter. |
| HTML / Web | In an HTML page, write ∪. Use \222A in CSS, \u222A in JavaScript and \u222A 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 sits directly on the following ClavierVirtuel layouts, where you can click it with the mouse:
Codes and encodings
| Property | Value |
|---|---|
| Code point | U+222A |
| Unicode block | Mathematical Operators (U+2200–U+22FF) |
| Decimal | 8746 |
| Hexadecimal | 0x222A |
| Octal | 021052 |
| Binary | 10001000101010 |
| UTF-8 bytes | 0xE2 0x88 0xAA |
| UTF-16 units | 0x222A |
| Named HTML entity | ∪ |
| Decimal HTML entity | ∪ |
| Hex HTML entity | ∪ |
| CSS escape | \222A |
| JavaScript escape | \u222A |
| Python escape | \u222A |
| URL encoding | %E2%88%AA |
Frequently asked questions
What is the Unicode code for ∪?
Its code point is U+222A, which is 8746 in decimal and 021052 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+222A. 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 %E2%88%AA. Modern filesystems accept it, though it is still risky when moving files between systems. For passwords, some forms reject non-ASCII characters outright.