∓
∓ Minus-Plus Sign
The minus-plus sign (∓) is the partner of ±. In an expression containing both, ∓ always takes the opposite sign to the ± — that is the whole reason it exists.
Also known as: minus plus symbol, minus or plus sign, upside down plus minus.
Codes
| Symbol | ∓ | |
| Plus-minus | ± · U+00B1 | |
| Unicode | U+2213 | |
| HTML entity (named) | ∓ | |
| HTML entity (decimal) | ∓ | |
| HTML entity (hex) | ∓ | |
| CSS | \2213 | |
| LaTeX | \mp | |
| Windows Alt code | Alt + 8723 |
How to type ∓ (Minus-Plus Sign)
Windows2213, Alt + X
In Word, type 2213 then press Alt + X. Elsewhere, copy ∓ above or use Character Map.
Mac
No default keystroke. Open Character Viewer (Control + Cmd + Space) and search “minus-or-plus”, or copy ∓ above.
Microsoft Word2213, Alt + X
Type 2213, then press Alt + X to convert it to ∓.
Google Docs
Insert → Special characters, then search “minus-or-plus”. In an equation, \mp followed by a space also works.
LaTeX\mp
Use \mp in math mode (\pm gives ±).
Usage
- ★ Why ∓ exists: it is only meaningful next to a ±, where it means “take the other one”. In cos(x ± y) = cos x cos y ∓ sin x sin y, choosing + on the left forces − on the right, and vice versa. One identity, two true statements.
- So ∓ is not a decorative flip of ±, and it is not interchangeable with it. Using ± twice in that identity would make it false half the time.
- You will meet ∓ mostly in trigonometric identities, in the quadratic-formula family, and in physics where two cases mirror each other.
- On its own — a measurement, a tolerance, an error bar — you want ±, not ∓. 5 ± 0.2 mm is a tolerance; 5 ∓ 0.2 mm says nothing without a matching ±.