A subscript is a small character set slightly below the baseline. Chemists use it to count atoms (H₂O, C₆H₁₂O₆), mathematicians and programmers to index variables (x₁, aₙ), physicists to label quantities (v₀, Eₖ) and musicians once used figures below the bass line in figured-bass notation. In a word processor you get a subscript with a formatting button (Ctrl + = in Word, Ctrl + , in Google Docs), but that formatting disappears as soon as the text is copied into a plain-text field.
Unicode solves this with dedicated subscript characters. All ten digits and the signs + − = ( ) have subscript forms, but only 17 Latin letters do, because they were added for phonetic transcription rather than as a complete alphabet. Capital letters have no subscripts at all, so the generator uses the lowercase form where one exists.
Two smart outputs save time: “Chemistry formatting” subscripts only the digits that follow an element or bracket (CO2 → CO₂, while charges like 2+ become superscript), and “Math formatting” converts the underscore notation used in LaTeX and spreadsheets, x_1 or a_{n+1}, into x₁ and aₙ₊₁.
How to use the Subscript Generator
- Text to convert
Everything is calculated in your browser, so results appear instantly and nothing you type is sent to a server.
How it works
Every character is looked up in a subscript table; characters without a subscript form are left unchanged and listed. The chemistry output applies subscripts only to digits following a letter or closing bracket, and the math output only to characters after an underscore.
Worked example
Input “H2O and CO2, x_1 + x_2”. The chemistry output is H₂O and CO₂, x_1 + x_2 (only digits after element symbols change). The math output is H2O and CO2, x₁ + x₂. Converting every character gives ₕ₂ₒ ₐₙd Cₒ₂, ₓ_₁ ₊ ₓ_₂ – “d” and capital “C” have no subscript form and stay normal.
Subscript characters
| Normal | 0 1 2 3 4 5 6 7 8 9 | + − = ( ) | a e o x ə h k l m n p s t |
|---|---|---|---|
| Subscript | ₀ ₁ ₂ ₃ ₄ ₅ ₆ ₇ ₈ ₉ | ₊ ₋ ₌ ₍ ₎ | ₐ ₑ ₒ ₓ ₔ ₕ ₖ ₗ ₘ ₙ ₚ ₛ ₜ |
Formula
Digits 0–9 → ₀–₉ (U+2080–U+2089) · + − = ( ) → ₊ ₋ ₌ ₍ ₎
Letters with subscript forms: a e h i j k l m n o p r s t u v x (and β γ ρ φ χ)
Worked example
Inputs — Text to convert: H2O and CO2, x_1 + x_2.
Results — Subscript text = ₕ₂ₒ ₐₙd Cₒ₂, ₓ_₁ ₊ ₓ_₂; Chemistry formatting (H2O → H₂O) = H₂O and CO₂, x_1 + x_2; Math formatting (x_1 → x₁) = H2O and CO2, x₁ + x₂; Superscript version = ᴴ²ᴼ ᵃⁿᵈ ᶜᴼ², ˣ_¹ ⁺ ˣ_²; Characters with no subscript form = d C , _; Characters = 22.
Key terms
- Subscript
- A small character placed below the baseline.
- Baseline
- The line on which most letters sit.
- Chemical formula
- Notation where subscripts count atoms, e.g. C₆H₁₂O₆.
Frequently asked questions
How do I type H₂O?
Type H2O and copy the “Chemistry formatting” result, or use the subscript ₂ (U+2082) directly.
Which letters can be subscript?
Only a, e, h, i, j, k, l, m, n, o, p, r, s, t, u, v and x, plus Greek β, γ, ρ, φ and χ.
Why are capital letters not converted?
Unicode has no subscript capitals; the generator uses lowercase subscripts where available.
How big is a subscript?
Typically 55–65% of the normal font size, lowered by about a third of the x-height; Unicode characters follow whatever the font designer chose.
What is the keyboard shortcut for subscript?
Ctrl + = in Microsoft Word and Ctrl + , in Google Docs (⌘ + = and ⌘ + , on Mac).
Can I use subscripts in Excel?
Inside a cell you can format characters as subscript, but pasted Unicode subscripts are simpler and survive in formulas and charts.
Are Unicode subscripts searchable?
Not reliably – a search for “CO2” will not find “CO₂”, so keep a plain version in metadata.