Plus-minus Sign Symbol
The ± plus-minus sign indicates “plus or minus” a given amount.
U+00B1
The ± (plus-minus) sign is commonly used to show two possible values. It’s especially popular in measurements, tolerances, and uncertainty ranges. Copy it directly or use the provided Unicode/escape codes in software.
Plus-minus Sign Symbol Meaning
The plus-minus sign (±) means “either plus or minus” a particular quantity. In everyday writing, it often expresses an uncertainty or range, such as “10 ± 2,” meaning the value may be 2 higher or 2 lower than 10. In measurements and engineering, it commonly appears as a tolerance, for example “50 ± 0.5 mm.” In some contexts, it can also indicate that a result could be one of two opposite cases (such as positive/negative outcomes), but its most recognizable use is uncertainty and tolerance notation.
Common uses
- •Expressing measurement uncertainty or error (e.g., 25 ± 3 °C)
- •Showing tolerances in manufacturing and specifications (e.g., 10.00 ± 0.01 m)
- •Writing ranges for calculations or estimates (e.g., 100 ± 5 units)
- •Indicating alternative sign conventions in formulas (e.g., ±n for a variable’s sign)
- •Formatting comparisons where a value may increase or decrease by the same amount (e.g., speed ±10%)
Examples
± Plus-Minus Sign (U+00B1)
- ±Temperature: 20 ± 2 °C
- ±Weight tolerance: 500 ± 25 g
- ±Voltage rating: 12 ± 0.5 V
- ±Estimated value: 1.25 ± 0.10
- ±Change: 300 ± 30 participants
Variations
Ready to copy
Technical codes
| Unicode | U+00B1 | |
| HTML Entity | ± | |
| HTML Code | ± | |
| CSS | \00B1 |
FAQ
What does the ± symbol mean?
It means “plus or minus,” indicating that a value may vary upward or downward by the stated amount.
How do I type or insert ± in a document?
You can copy it directly as “±”, or enter its Unicode character U+00B1 (HTML: ±).
When should I use ± versus a range like “10 to 12”?
Use ± when you want to show deviation from a central value (e.g., “10 ± 2”). Use a range like “10 to 12” when you only need the endpoints.
Is ± only used in math and science?
It’s most common in measurements and technical specs, but it’s also used in general writing to indicate uncertainty, tolerances, or allowable variation.