±Plus-minus symbol
Plus or minus, for tolerances and margins of error.
- Unicode
- U+B1
- Alt code
- Alt+177
- HTML
- ±
- Unicode name
- Plus-Minus Sign
Where the Plus-minus symbol comes from
The plus-minus sign appeared in the seventeenth century as a compact way to write two results at once — the quadratic formula being the case that made it indispensable. Its use for measurement tolerance came much later, from engineering drawings.
Tolerances and error bars: 20 ± 0.5 mm, 48% ± 3. In statistics it introduces a confidence interval, in electronics a component rating, and in weather forecasts a temperature range.
Plus-minus symbol codes
Tap any value to copy it. All of them produce the same character — they just belong to different places.
How to type ± on any keyboard
Pick the route that matches the program in front of you.
Will ± actually show up?
We checked 147 fonts installed on a normal machine and counted how many of them contain this character. A symbol missing from a font is drawn as an empty box — the text is still correct, it just cannot be drawn.
Safe everywhere. This one is in almost every font ever installed, including the defaults on Windows, Mac and Android.
Symbols people confuse with ±
Lookalikes that are not the same character at all — separate codes, separate fonts, and here they number 8.
Other mathematical symbols
Symbols from the same family, each with its own page: where it came from, how to type it and how well fonts support it.
Math symbols
Operators, set theory, logic, calculus — everything past the number row.