The plus-minus sign ± is Alt+0177 on Windows and Option+Shift+= on a Mac. It states a tolerance or a margin of error, as in 20mm ± 0.5mm. In algebra it signals that an equation has two solutions, one for each sign.
01 All shortcuts at a glance
| Platform | Shortcut | |
|---|---|---|
| Windows (Alt code) | Hold Alt, type 0177 on the numpad |
|
| Windows (any app) | Win+. or Win+; emoji/symbol picker, or Character Map (Win+R → charmap) |
|
| Mac | Control+Command+Space to open Character Viewer, search "Plus-Minus Sign" |
|
| Word / Outlook | Type 00B1, then press Alt+X |
|
| Linux (IBus) | Ctrl+Shift+U, then 00b1, then Enter |
|
| HTML / CSS | ± · \00b1 (CSS) |
02 Step by step, per platform
A real, followable procedure for every platform, not a thin restatement of the shortcut.
Windows
- Make sure Num Lock is on.
- Hold Alt and type 0177 on the numeric keypad.
- Release Alt, ± appears.
Mac
- Press Control+Command+Space to open the Character Viewer.
- Type "Plus-Minus Sign" in the search field.
- Double-click the result to insert it.
Microsoft Word
- Type 00B1.
- Press Alt+X immediately after, it converts the hex code to ±.
03 Characters in this set
04 Troubleshooting & confusables
| Looks like it | But it's actually | When to use |
|---|---|---|
| ∓ (U+2213) | Minus-or-plus sign, the reversed order | Paired with ± in one expression when the two signs must be opposite. |
| +/- | Three ASCII characters | A plain-text fallback. Use the real symbol wherever the encoding allows. |
| + over - | Two stacked characters | A layout workaround. The single character spaces correctly and copies as one unit. |
05 FAQ
What is the Unicode code point for the plus-minus sign?
It is U+00B1, decimal 177. Alt+0177 types it on Windows.
What does ± mean in a measurement?
It gives the tolerance either side of a value. A part listed as 20mm ± 0.5mm is acceptable anywhere from 19.5mm to 20.5mm.
What does it mean in an equation?
It compresses two solutions into one line. The quadratic formula uses it because a quadratic normally has two roots, one from the plus and one from the minus.
What is the ∓ symbol for?
It is the minus-or-plus sign at U+2213. When both appear in one expression, they must take opposite signs, so choosing plus for ± forces minus for ∓.
Are there spaces around it?
In a tolerance, yes, as in 20 ± 0.5. When it acts as a sign on a single value it closes up, as in ±5.