What is the Milesian or alphabetic numeral system?

It is the classical Greek way of writing numbers using the 24 letters of the alphabet plus three archaic letters. Alpha through theta cover 1 to 9, iota through koppa cover the tens, and rho through sampi cover the hundreds.

What are stigma, koppa and sampi?

They are three letters retained only as numerals: stigma is 6, koppa is 90 and sampi is 900. The Greek alphabet alone has 24 letters, so these three fill the gaps needed to reach 27 numeral symbols for units, tens and hundreds.

How are thousands written?

Thousands from 1000 to 9000 reuse the unit letters alpha to theta but with a keraia mark, a small stroke, placed before and below the letter. This tool prefixes the thousands letters with the lower keraia character.

Is a keraia added to ordinary numerals?

Yes. In manuscripts a keraia, an upper stroke, often follows a numeral to mark it as a number rather than a word. This tool appends the upper keraia to the units-tens-hundreds group.

What is the largest supported number?

The standard alphabetic system reaches 9999 cleanly using the keraia for thousands. Above that, scribes used the myriad letter M with multipliers, which this tool does not encode; it accepts 1 to 9999.

Greek Numeral System Converter

The classical Greek alphabetic, or Milesian, numeral system assigns a value to each letter: alpha to theta for the units, iota to koppa for the tens, and rho to sampi for the hundreds. This converter turns an integer into that notation, including the archaic letters stigma, koppa and sampi.

How it works

The number is split into hundreds, tens and units, and each digit selects a letter from one of three nine-symbol rows:

units    α β γ δ ε ϛ ζ η θ      (1–9, ϛ = stigma = 6)
tens     ι κ λ μ ν ξ ο π ϟ      (10–90, ϟ = koppa = 90)
hundreds ρ σ τ υ φ χ ψ ω ϡ      (100–900, ϡ = sampi = 900)

Thousands (1000–9000) reuse the unit letters but are prefixed with the lower keraia mark ͵. The complete numeral is the thousands group followed by the hundreds-tens-units group, with an upper keraia ʹ appended to mark the whole as a number.

Example and tips

241 is written σμαʹ — sigma (200) + mu (40) + alpha (1). The year 1453 becomes ͵αυνγʹ: the lower keraia plus alpha for 1000, then upsilon (400), nu (50) and gamma (3). Remember that 6, 90 and 900 use the special letters, so they will look unfamiliar if you only know the modern 24-letter alphabet.