Statistics Symbols (x̄ μ σ ∑ ρ χ²) and How to Type Them

How-To Guides · 2 min read · Published October 25, 2026

Quick answer: the most used statistics symbols are x̄ (sample mean), μ (population mean), σ and s (standard deviation), ∑ (sum), ρ and r (correlation) and χ² (chi-square). Only σ (Alt+229), ± and √ have Windows Alt codes among them. x̄ and p̂ are not single characters: they are a letter followed by a combining mark, typed in Word as x0304 then Alt+X.

Quick reference: every method

Every Alt code below is verified against the real Windows code pages — where none exists we say so, rather than list one that won’t work.

Population vs sample

Other common signs: ∑ (sum of values), χ² (chi-square), α (significance level), β (regression coefficient or type II error), H₀ and H₁ (hypotheses), ≈ (approximately) and ± (margin of error).

Typing x̄, p̂ and ŷ

Unicode has no ready-made "x with bar" character. Instead you type the letter, then a combining mark that attaches to it:

• Bar (macron): U+0304, so x̄ = x + 0304.
• Hat (circumflex): U+0302, so p̂ = p + 0302. (ŷ also exists as a single character, U+0177.)

In Word, type x0304 and press Alt+X: Word converts only the code and the bar lands on the x. (If Word grabs the x too, select just the four digits first.) Pressing Backspace once removes only the bar. In a Word equation (Alt+=), type x\bar then a space, or p\hat. Some fonts place combining marks slightly off-centre; Cambria Math and other maths fonts look best.

Greek letters

• Windows: σ Alt+229 is a real Alt code. μ, ρ and χ have none: in Word type 03BC, 03C1 or 03C7 and press Alt+X.
• Mac: the Character Viewer (search "mu", "sigma") or the Greek keyboard. Option+M types the micro sign µ, not the Greek μ; use the Greek letter for the mean.

Full details for every letter are in how to type Greek letters.

Excel and Google Sheets

Use labels such as =UNICHAR(963) for σ or =UNICHAR(956) for μ. For x̄ in a header, paste the two-character sequence from this page. The calculations themselves use functions: AVERAGE, STDEV.S (sample s), STDEV.P (population σ), CORREL (r).

LaTeX

\bar{x}, \hat{p}, \mu, \sigma, \sum, \rho, \chi^2, H_0. See LaTeX math symbols.

Related: calculus symbols (∑ and ∏), ± plus-minus and our summation symbols.

Frequently asked questions