Delta Symbol (Δ / δ): How to Type, Copy, and Use It
The delta symbol, Δ, is the Greek triangle that means “change” — ΔT is a change in temperature, Δx a change in position. Its lowercase form δ marks a tiny change, and there’s a near-identical maths symbol, ∆, that specifically means “the difference.” None of them are on an English keyboard, so most people copy them or use a shortcut. This page has all three, plus what delta means across science, finance, and code.
If you just need the symbol, copy Δ (or δ, or ∆) from the grid below. If you want the shortcuts and the meaning, the sections below cover both.
In a hurry?
- Copy it: click Δ in the grid below.
- On Windows: hold Alt and type 916 for Δ (948 for δ).
- On a Mac: press Option + j for the change sign ∆.
- In Word: type 0394 then press Alt + X for Δ.
- In HTML: write Δ (or Δ).
Table of Contents
Copy and paste the delta symbol
Delta in its three forms, with the codes you’re likely to need. Use the grid above to copy with one click; this table is the reference.
| Symbol | Name | Unicode | Windows | HTML |
|---|---|---|---|---|
| Δ | Greek capital delta | U+0394 | Alt + 916 | Δ |
| δ | Greek small delta | U+03B4 | Alt + 948 | δ |
| ∆ | increment (change) | U+2206 | Alt + 8710 | ∆ |
| ∂ | partial derivative | U+2202 | Alt + 8706 | ∂ |
None of these are on a standard keyboard, so each takes a shortcut, a code, or a copy. The sections below cover each device, then the difference between the Greek letter and the change symbol.
How to type the delta symbol on any device
Type Δ on Windows
Use the Alt code: turn on Num Lock, hold Alt, and type 916 on the numeric keypad for Δ, or 948 for δ. For the change sign ∆, use Alt + 8710. On a laptop with no keypad, press Windows + . and search “delta.”
Type Δ on Mac
On a Mac, Option + j gives the change sign ∆ directly — handy for maths. For the Greek letter Δ specifically, use the Character Viewer (Control + Command + Space) and search “delta,” or add a Greek keyboard, where Δ sits on the D key.
Type Δ on iPhone and Android
Neither phone keyboard has Δ as standard. Add a Greek keyboard in settings and Δ is on the D key; otherwise copy it from the grid above. Some scientific-calculator keyboards include the ∆ change sign.
Type Δ in Microsoft Word
Type 0394 then press Alt + X for Δ (use 03B4 for δ, or 2206 for the change sign ∆). Or use Insert → Symbol, where the Greek letters and operators are listed. In the equation editor (Alt + =), \Delta and \delta work.
Type Δ on Linux
Press Ctrl + Shift + U, type 0394, then Enter for Δ (03b4 for δ, 2206 for ∆). Adding a Greek keyboard layout also puts Δ on the D key.
Add Δ in HTML and CSS
In HTML, Δ is Δ (capital) or δ (lowercase), or the numeric Δ. In CSS, a Δ in a content value is the escaped code point \0394.
Δ the Greek letter vs ∆ the change operator
As with the summation sign, there are two nearly identical delta triangles that are actually different characters. The Greek capital delta Δ is U+0394, a letter of the Greek alphabet. The increment sign ∆ is U+2206, a dedicated mathematical symbol meaning “change” or “the difference.” On screen they look the same, but they’re catalogued differently and read differently by software and screen readers.
In practice, most people just use the Greek Δ for everything, including “change in” (ΔT, Δx), and it’s universally understood that way. The increment ∆ (U+2206) is the technically precise character for the maths operator, and it’s what a Mac’s Option + j produces. For everyday writing, the Greek Δ is perfectly fine; if you’re typesetting formal maths and want the exact operator, use ∆. It’s the same situation as the [summation symbol](/summation-symbol/), where the operator and the Greek letter overlap.
| Character | Name | Use it for |
|---|---|---|
| Δ | Greek capital delta (U+0394) | “change,” the letter, most uses |
| ∆ | increment sign (U+2206) | the precise maths operator |
| δ | Greek small delta (U+03B4) | a tiny change |
Delta means ‘change’: ΔT, Δx, and delta as a word
The single most useful thing to know about Δ is that, in front of a variable, it means “the change in”. ΔT is the change in temperature, Δx the change in position, Δt an interval of time, ΔV a change in volume or voltage. You calculate it by subtracting: Δx = x₂ − x₁ (the final value minus the starting value). So “delta” is shorthand for “how much did this change.”
The word has escaped maths entirely. People now say “delta” to mean any difference or gap: the delta between budgeted and actual spend, the delta between two versions of a document, “what’s the delta here?” in a meeting. It’s become a slightly geeky synonym for “the difference” — which is exactly what the symbol meant all along. Whenever you see Δ, read it as “change in,” and the formula usually makes sense.
| Written | Means |
|---|---|
| ΔT | change in temperature |
| Δx | change in position |
| Δt | time interval |
| “the delta” | the difference / gap |
Lowercase δ: small change and the delta of calculus
The lowercase δ is delta’s quieter sibling, and it usually means a very small change — smaller and more precise than the capital Δ. Where ΔT might be a temperature swing of ten degrees, δT suggests a tiny, almost infinitesimal nudge. In calculus, δ appears in the famous delta-epsilon (δ–ε) definition of a limit, where δ is a tiny distance you can make as small as you like.
There’s a related symbol worth not confusing with it: the partial derivative sign ∂ (U+2202), a curly d, used for the rate of change of a function with respect to one variable while holding others fixed. So the family runs from big to small: Δ a change, δ a tiny change, ∂ a change in one direction only. They look related on purpose — all are “change” symbols — but each is its own character with its own precise job.
The delta shape: the triangle and river deltas
Delta is the fourth letter of the Greek alphabet, the ancestor of our letter D, and its capital form is a clean triangle — which turns out to be why a river mouth is called a “delta.”
When the ancient Greek historian Herodotus described the mouth of the Nile, where the river fans out into a broad triangular plain before the sea, he noted it was shaped like the letter Δ — and the name stuck. Ever since, any triangular deposit of sediment at a river’s mouth is a delta: the Nile Delta, the Mississippi Delta, the Ganges Delta. So the same triangle that means “change” in a physics equation also names some of the most fertile land on Earth, all because a capital delta looks like a river spreading out. The letter’s shape has been doing double duty for 2,500 years.
Delta everywhere: finance, rockets, code, and NATO
Because “delta” is such a handy word for change, it has spread into a surprising number of fields. In finance, an option’s delta measures how much its price moves when the underlying asset changes — a direct use of Δ as “rate of change.” In spaceflight, delta-v (Δv) is the change in velocity a rocket can produce, the single most important number in mission planning.
In software, a delta is a diff — the set of changes between two versions of a file, which is how version control and efficient backups work (store the delta, not the whole file). And in the NATO phonetic alphabet, Delta simply stands for the letter D (Alpha, Bravo, Charlie, Delta). The airline, the Mississippi region, the COVID variant — all borrow the same short, punchy word. Whatever the field, it comes back to the triangle that means “change.”
Δ in URLs and encoding
In a URL, Δ is percent-encoded as %CE%94 (its two UTF-8 bytes); the increment sign ∆ is %E2%88%86. In code, the escape for the character in a string is \u0394 for Δ and \u03B4 for δ. If Δ ever shows as garbled characters or a box, the page is being read in the wrong encoding — serve it as UTF-8.
Copy-paste HTML codes
Every code for the delta symbols in one place. Click a cell and copy.
| Symbol | Named entity | Numeric entity | URL (percent) code |
|---|---|---|---|
| Δ | Δ | Δ | %CE%94 |
| δ | δ | δ | %CE%B4 |
| ∆ | — | ∆ | %E2%88%86 |
| ∂ | ∂ | ∂ | %E2%88%82 |
In a CSS content value, use \0394 for Δ. For the summation operator, which shares the Greek-letter-vs-operator issue, see the [summation symbol](/summation-symbol/) guide; for every Greek letter and operator, the [math symbols Alt codes](/math-symbols-on-keyboard-alt-codes/) reference.
Troubleshooting
My Δ shows as a box or garbled text
That’s an encoding mismatch: the UTF-8 bytes for Δ are being read as an older encoding. Set the file, database, and page charset to UTF-8 and Δ displays correctly.
Which delta should I use for ‘change’?
The Greek capital Δ (U+0394) is fine and universally understood for “change in” (ΔT, Δx). If you want the precise maths operator, use the increment sign ∆ (U+2206), which is what a Mac’s Option + j types.
Alt + 916 isn’t working
That decimal code needs app support. If it fails, type 0394 then Alt + X in Word, use the Character Viewer on a Mac, or copy Δ from the grid above.
FAQ
How do I type the delta symbol?
On Windows, hold Alt and type 916 for Δ (948 for δ). On a Mac, Option + j gives the change sign ∆. In Word, type 0394 then Alt + X. In HTML, write Δ. Or click Δ in the grid above.
What does the delta symbol mean?
In front of a variable it means “change in”: ΔT is a change in temperature, Δx a change in position, calculated as the final value minus the starting value. More loosely, “delta” means any difference or gap.
What’s the difference between Δ and ∆?
Δ (U+0394) is the Greek capital letter delta; ∆ (U+2206) is the increment sign, a maths symbol for “change.” They look identical, and the Greek Δ is widely used for both. Use ∆ when you want the precise operator.
What is the lowercase δ used for?
A very small change, smaller than the capital Δ suggests, as in the delta-epsilon definition of a limit. Don’t confuse it with the partial derivative sign ∂, a curly d.
How do I write Δ in HTML?
Use Δ (capital) or δ (lowercase), or the numeric Δ. In a URL, Δ is percent-encoded as %CE%94.
