Counting in Latin

Language overview

Forty-two in Latin Latin (lingua Latina, sermo Latinus) is an Italic language originally spoken in Latium and Ancient Rome, from II BC to II AD, then through the Middle Ages. Extinct language to the extend it has no native speaker, Latin is still one of Vatican City co-official languages (alongside with French, German and Italian).

Due to lack of data, we can only count accurately up to 9,999 in Latin. Please contact me if you can help me counting up from that limit.

Latin numbers list

  • 1 – unus
  • 2 – duo
  • 3 – tres
  • 4 – quattuor
  • 5 – quinque
  • 6 – sex
  • 7 – septem
  • 8 – octo
  • 9 – novem
  • 10 – decem
  • 11 – undecim
  • 12 – duodecim
  • 13 – tredecim
  • 14 – quattuordecim
  • 15 – quindecim
  • 16 – sedecim
  • 17 – septendecim
  • 18 – duodeviginti
  • 19 – undeviginti
  • 20 – viginti
  • 30 – triginta
  • 40 – quadraginta
  • 50 – quinquaginta
  • 60 – sexaginta
  • 70 – septuaginta
  • 80 – octoginta
  • 90 – nonaginta
  • 100 – centum
  • 1,000 – mille

The Roman numeration

The Roman numbers are formed from seven letters or symbols: I [1], V [5], X [10], L [50], C [100], D [500], and M [1,000]. Used in ancient Rome and during the Middle Ages, they allow to count up to 4,999 through a both additive and subtractive system. To form a number, we add the symbols from left to right until we get three identical symbols (this is the additive part: I, II, III, XXII), then we place on the left side of the bigger symbol the number to subtract (this is the subtractive part: IV, IX, XC). The same symbol cannot be used more than three times in a row, except for M (MMMM is 4,000). Unlike the decimal system, it is an additive system where each symbol has its own value, independent of where it is placed.

To be valid, a number written in Roman characters must follow these rules:

  • the Roman digits can only be repeated three times at most (VIII is valid, but VIIII is not)
  • the numbers D, L et V can only be repeated once (DD, LL and VV are not valid)
  • only one C can be placed before an M (CM, or 900, is valid, CCM is not) or a D (CD, or 400, is valid, CCD is not) and the following values cannot be greater than 99 (or we would jump to the next hundred)
  • only one X can be placed before a C (XC, or 90, is valid, XXC is not) or an L (XL, ou 40, is valid, XXL is not) and the following values cannot be greater than 9 (or we would jump to the next ten)
  • only one I can be placed before an X (IX, or 9, is valid, IIX is not) or a V (IV, ou 4, is valid, IIV is not)

1 000

Latin numbering rules

Now that you’ve had a gist of the most useful numbers, let’s move to the writing rules for the tens, the compound numbers, and why not the hundreds, the thousands and beyond (if possible).

  • Numbers from zero to ten are specific words, namely nulla [0], unus/una/unum (m/f/n) [1], duo/duae/duo (m/f/n) [2], tres/tres/tria (m/f/n) [3], quattuor [4], quinque [5], sex [6], septem [7], octo [8], novem [9], and decem [10].
  • From eleven to seventeen, numbers are formed from the root of the digit followed by ten: undecim [11], duodecim [12], tredecim [13], quattuordecim [14], quindecim [15], sedecim [16], and septendecim [17]. Eighteen and nineteen are formed on a subtracting manner: duodeviginti [18] (literally two from twenty), and undeviginti [19] (one from twenty).
  • The tens have specific names based on the matching digit root except for ten and twenty: decem [10], viginti [20], triginta [30], quadraginta [40], quinquaginta [50], sexaginta [60], septuaginta [70], octoginta [80], and nonaginta [90].
  • Compound numbers are formed by setting the ten, then the unit, separated with a space when the unit digit goes from one to seven, following the additive structure (e.g.: viginti unus [21], triginta duo [32]). When a compound number ends with eight or nine, the additive structure (ten plus unit) is replaced by the subtracting structure (next ten minus unit), with no space (e.g.: duodequinquaginta [48] (literally two from fifty), undesexaginta [59] (one from sixty), nonaginta octo [98] (which is an exception to the rule), undecentum [99] (one from one hundred)).
  • The hundreds are formed by prefixing the word hundred by the multiplier digit root, except for one hundred: centum [100], ducenti [200], trecenti [300], quadringenti [400], quingenti [500], sescenti [600], septingenti [700], octingenti [800], and nongenti [900].
  • Thousands are formed by prefixing the word thousand by the multiplier digit, except for one thousand: mille [1,000] (plural milia), duo milia [2,000], tria milia [3,000] (using the neuter from of three), quattuor milia [4,000], quinque milia [5,000]… In singular, the word mille is an indeclinable adjective, but in plural, this is a noun following the third declension neuter i-stem.

Write a number in full in Latin

Let’s move now to the practice of the numbering rules in Latin. Will you guess how to write a number in full? Enter a number and try to write it down in your head, or maybe on a piece of paper, before displaying the result.


A Latin Grammar A Latin Grammar
by , editors Oxford University Press (2000)

Essential Latin Essential Latin
by , editors Routledge (1999)
[, Kindle - Kindle -]

Gramatica latina Gramatica latina
editors Editorial Porrua (2008)

Gramatica de la lengua latina Gramatica de la lengua latina
by , editors Nabu Press (2010)

Grammaire latine complète Grammaire latine complète
by , editors Eyrolles (2010)

Grammaire latine Grammaire latine
by , editors Nathan (1991)

Gramática de Latim Gramática de Latim
by , editors Presença (2000)

Romance languages

Asturian, Catalan, Corsican, Eonavian, French, Friulian, Galician, Gallo, Italian, Jèrriais, Ladin, Latin, Lombard (Milanese), Occitan, Picard, Portuguese (Brazil), Portuguese (Portugal), Romansh, Sardinian, Spanish, and Venetian.

Other supported languages

As the other currently supported languages are too numerous to list extensively here, please select a language from the full list of supported languages.

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