Greek Numerals Converter
Type a Greek numeral to read it as a number, or a number to see how Greek wrote it. Works in both directions, handles the thousands mark, and shows which letter contributed what.
How the System Works
Greek had no separate digits. The alphabet did both jobs, which is why a Greek number looks like a word and why reading one is mostly a matter of knowing which rank each letter belongs to.
There are three ranks of nine. Alpha to theta are the units, 1 to 9. Iota to koppa are the tens, 10 to 90. Rho to sampi are the hundreds, 100 to 900. A number is written from the highest value down, and the values are simply added: σμζ is 200 plus 40 plus 7, or 247.
Because it is purely additive there is no place value, no zero, and no way of writing a negative. There is also no ambiguity: the order is a convention for readability, and the total would be the same in any arrangement.
The Two Marks
A keraia, written after the letters as a small raised stroke, marks the group as a number rather than a word. Without it, iota-beta is a syllable; with it, it is twelve.
A second mark below and to the left of a letter multiplies it by a thousand. So alpha alone is 1, but alpha carrying that mark is 1,000, and the ladder starts again. This is how the same 27 symbols reach 9,999.
Above that, Greek switched to myriad notation, writing multiples of 10,000 with a separate marker. The conventions there vary between sources, so this converter stops at 9,999 rather than picking one and presenting it as standard.
The Three Letters That Are Only Numbers
ϛ / ϝ — 6
Stigma or digamma. Digamma is the older letter, stigma the ligature most printed editions use. Both are read as 6 here.
ϟ / ϙ — 90
Koppa, in its numeral form and its archaic letter form. Both are read as 90.
ϡ — 900
Sampi, which closes the hundreds rank and appears in no ordinary Greek word.
None of the three survives in the 24 letter alphabet taught for reading Greek, because all three had dropped out of speech. They stayed because the arithmetic needed 27 symbols and the alphabet only offered 24.
Worked Examples
12 is iota plus beta: 10 + 2. 90 is koppa alone, a single letter that never appears in words. 247 is sigma, mu, zeta: 200 + 40 + 7. 666 is chi, xi, stigma: 600 + 60 + 6, which is how the number appears written out in the manuscripts of Revelation. 1821 takes the thousands mark on alpha, then omega, kappa, alpha: 1000 + 800 + 20 + 1.
Where You Will Meet These
Dates and chapter numbers in editions of Greek texts, page numbering in older books, inscriptions, manuscript foliation, and the numbering of the books of the Iliad and Odyssey, which use the 24 letters of the alphabet directly. Modern Greek still uses the system for ordinals in formal contexts, much as English uses Roman numerals.
If you are copying from a digital corpus you may meet the text in Beta Code rather than Greek characters. The Beta Code guide covers that scheme and how to get real Greek out of it.
Numerals Against Isopsephy
These are two different uses of one set of values, and confusing them produces nonsense. On this page the letters are a number: sigma-mu-zeta means 247 and spells nothing. In isopsephy the letters spell a word and their values are added to give that word a total, so λογος is a word meaning logos which happens to total 373.
The arithmetic is identical; the intent is not. To go the other way and calculate a word rather than read a numeral, use the isopsephy calculator. The full value table for both jobs is on the Greek chart.
Frequently Asked Questions
How do Greek numerals work?
Each letter carries a value in three ranks of nine: alpha to theta are 1 to 9, iota to koppa are 10 to 90, and rho to sampi are 100 to 900. A number is written highest value first, so 247 is sigma, mu, zeta.
What is the mark after the letters?
The keraia, a small stroke that marks the letters as a number rather than a word. A second mark written below and to the left of a letter multiplies it by a thousand.
Why are there letters I do not recognise?
Digamma or stigma at 6, koppa at 90 and sampi at 900 left ordinary Greek writing but stayed in the numeral system, because 27 values cannot be written with a 24 letter alphabet.
Did Greek have a zero?
Not in this system. Milesian numerals are additive and start at 1, so there is no zero, no negative numbers and no place value.
Is this the same as gematria?
No. Here the letters are the number. In isopsephy the letters spell a word and their values are added to give that word a total. The same letter values serve both jobs.