Greek numerals

Published junio 28, 2026 · By NumberWiki

The Greek (or Milesian) numeral system turns the alphabet into numbers: the first nine letters are the ones, the next nine the tens, the next nine the hundreds. It's the system Archimedes, Diophantus, and Ptolemy wrote their mathematics in, and a version of it is still used ceremonially in Greece today, much as Roman numerals are in the West.

Three rows of nine

The classical Greek alphabet has 24 letters — not quite enough, since the system needs 27 (nine ones, nine tens, nine hundreds). So the Greeks kept three archaic letters that had otherwise fallen out of the written language, purely for counting:

Ones (1–9): α β γ δ ε ϛ ζ η θ — where ϛ (digamma/stigma) is 6.
Tens (10–90): ι κ λ μ ν ξ ο π ϟ — where ϟ (koppa) is 90.
Hundreds (100–900): ρ σ τ υ φ χ ψ ω ϡ — where ϡ (sampi) is 900.

A number is then just the sum of its letters, largest first: 12 is ιβ (10 + 2), 256 is σνϛ (200 + 50 + 6), 837 is ωλζ (800 + 30 + 7). Because each letter has a fixed value, like Roman numerals it's a sign-value system with no need for a zero.

The keraia marks

Since the numerals are letters, Greek needs a way to signal "this is a number, not a word." A small stroke called the keraia (ʹ) is written at the upper right of a numeral — so αʹ is the number 1, βʹ is 2. For thousands, a lower keraia (͵) is written to the lower left: ͵α is 1,000, ͵β is 2,000. Combine the two and you can write any number up to 9,999: ͵αϡϟθʹ is 1,999 (1,000 + 900 + 90 + 9).

For genuinely large numbers — Greek astronomy needed them — scribes used the myriad (Μ, 10,000) with the multiplier written above or beside it, and Archimedes famously built a whole system of "myriad myriads" in The Sand Reckoner to express numbers large enough to count the grains of sand that would fill the universe.

From Attic to Milesian, and after

This wasn't Greece's first numeral system. The earlier Attic (or acrophonic) numerals worked more like Roman ones, using the first letters of number words (Π for pente, 5; Δ for deka, 10). The alphabetic Milesian system spread from Ionia and had largely replaced Attic by the Hellenistic period, becoming the standard across the Greek-speaking world for over a thousand years — through Byzantine times.

Like Roman numerals in the Latin West, Greek numerals never entirely went away. Modern Greece still uses them ceremonially and formally: regnal ordinals (Κωνσταντῖνος Αʹ — Constantine I), the numbering of chapters and legislative articles, and the names of organisations all routinely use Milesian numerals.

Reading Greek numerals on this site

NumberWiki renders Greek numerals for 1 to 999,999, with the keraia marks applied automatically and the archaic letters ϛ, ϟ, ϡ in their proper places. Every number page shows the Greek form in its Historical numeral systems section.