Plus-Minus Sign (±) in Professional Writing
The plus-minus sign is a dedicated character rather than a decorative pairing of plus and minus marks. Unicode identifies it as U+00B1 PLUS-MINUS SIGN. Its exact mathematical or technical interpretation depends on the field, so professional copy should preserve the notation required by the source or governing standard.
Use the true plus-minus character “±” when the notation calls for plus-or-minus; do not replace it casually with unrelated punctuation.
Key details
Important caveats
Technical Boundary
Do not infer a specific statistical or measurement interpretation from the symbol alone; the surrounding field and source define what ± represents.
Usage Boundary
Use ± only where the notation actually means plus-or-minus in the relevant mathematical, scientific, or technical context.
Further guidance
Character Identity
Unicode identifies ± as U+00B1 PLUS-MINUS SIGN.
Practical Application
Use the dedicated plus-minus character “±” when the notation calls for plus-or-minus, and preserve the notation used by the governing technical or editorial standard.
Reader Check
Check both character and meaning: use U+00B1 “±,” not an improvised “+/-,” unless the target system requires ASCII; do not assume the symbol has the same technical interpretation in every field.
Worked Example
Preferred typography: “10 ± 2” when that notation is required. Avoid silently changing the symbol or its spacing without the relevant style or technical rule.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Latin-1 Supplement — Unicode Names List (opens in a new tab)Unicode Consortium · Unicode character identities for degree sign, plus-minus sign, and multiplication sign