The plus minus symbol (±)
The plus minus symbol does two jobs at once: in measurements it states the tolerance or error around a value — 20 ± 2 °C means “somewhere between 18 and 22” — and in equations it packs two answers into one line. The sign reads both ways on purpose: plus or minus. This page copies the sign and its reversed partner, shows the usage patterns that matter, and gives the keyboard and code routes for every platform.
Copy the plus-minus signs
Most work needs only the first card. The second, ∓ (minus-or-plus), exists for paired formulas — explained below.
What ± means in practice
| Context | Reading | Example |
|---|---|---|
| Measurement tolerance | “give or take” — the true value sits inside the range | Length 100 ± 0.5 mm → between 99.5 and 100.5 mm |
| Statistics | spread around an average — mean ± standard deviation | Score 72 ± 8 (mean 72, SD 8) |
| Equations | two solutions in one line — one with +, one with − | x = (−b ± √D) / 2a in the quadratic formula |
| Everyday shorthand | approximate quantity in chat and listings | “Arriving 7 ± 1 pm” — informal, playful usage |
Ready-made examples to copy
± versus ∓: when the order flips
Read the plus minus sign top-first: upper operation first. Its mirror, ∓, flips the pairing, and the two appear together in identities where one quantity uses + while the other must use −: sin(x ± y) = sin x cos y ± cos x sin y keeps the same sign throughout, while cos(x ± y) = cos x cos y ∓ sin x sin y deliberately pairs + on the left with − on the right. In plain writing only ± is needed; ∓ belongs to formulas where the pairing carries meaning.
How to type the plus-or-minus sign
| Platform | Method |
|---|---|
| Windows | Alt + 0177 on the numeric keypad (or Alt + 241 on some layouts) |
| Mac | Option + Shift + = |
| Microsoft Word | Type 00B1 then press Alt + X |
| HTML | ± or ± |
| LaTeX | \pm (and \mp for ∓) |
| Phone | Long-press the + or = key on many keyboards, or copy from this page |
Whatever the plus or minus sign is called in speech — plus minus, plus or minus symbol — it is one character: U+00B1 in the Latin-1 block, which is why it renders everywhere from spreadsheets to PDFs without font surprises.
Explore more
The full operator family lives on the math symbols hub, and every sign’s name and code is listed in the symbol names and meanings guide.
Frequently asked questions
What does ± mean in a measurement?
Uncertainty: the value after ± is the range on either side. 50 ± 2 means the true value lies between 48 and 52.
Is plus-minus the same as “approximately”?
Close cousins, different claims: ± states an explicit range around a value; ≈ (approximately equal) just says “nearly”. Use ± when you can name the range.
Why does ∓ exist?
For paired formulas: when ± appears on one side of an identity, ∓ on the other side instructs the opposite operation for each case — see the trig examples above.
What is the Alt code for ±?
Alt + 0177 on Windows with a numeric keypad. In Word, 00B1 followed by Alt + X also works.
Does ± work in Excel and Google Sheets?
Yes — it is an ordinary text character (U+00B1); paste it into a cell or type it with the Alt code. Note it is text, not an operator: formulas still need real + and − signs.