French numbers to words converter (JavaScript)

This package converts numbers to their written forms in French language

The Rules

The units

less than 16 follow no rules but each has a specific name.”zéro”, “un”, “deux”, “trois”, “quatre”, “cinq”, “six”, “sept”, “huit”, “neuf”, “dix”, “onze”, “douze”, “treize”, “quatorze”, “quinze”, “seize”(from 0 to 16)

The tens

as French up to 60, or using Belgium-French (septante, huitante, nonante), up to 90, follow the same pattern.

• “dix”,
• “vingt”,
• “trente”,
• “quarante”,
• “cinquante”,
• “soixante”,
• “septante”,
• “huitante”,
• “nonante”(from 10 to 90)”huitante” could also be “octante”. In French from France, the pattern change at 70:
• 70 = 60 + 10 = “soixante-dix”
• 80 = 4 * 20 = “quatre-vingts”
• 90 = 4 * 20 + 10 = “quatre-vingt-dix”

Numbers from 22 to 29, then 32 to 39 …

• 22 = 20 + 2 = “vingt-deux”, with a dash in between From 17 to 19, it follows this rule
• 17 = 10 + 7 = “dix-sept”

Numbers ending with 1:

The rule is the same as above, but with “-et-” which means “and” instead of “-“:

• 21 = “vingt-et-un” Before 1990, the writing was “vingt et un” but since the 1990 simplification reform, all words used for numbers are joined-up with dashes.

Numbers after 70 and 90

• 74 = 60 + 14 = “soixante-quatorze”
• 77 = 60 + 17 = 60 + 10 + 7 = “soixante-dix-sept”
• 95 = 4 * 20 + 15 = “quatre-vingt-quinze”
• 99 = 4 * 20 + 10 + 9 = “quatre-vingt-dix-neuf”

plurals of “quatre-vingt”:

• 80 : 4 * 20 = “quatre-vingts” → means 4 times 20 so 20 is plural, thus “vingts” ends with an “s”. But when it is not the ending of the word, the plural form disappear:
• 82 = 4 * 4 +2 = “quatre-vingt-deux”, without an “s” at “vingt”.

71, 81, 91

For some unknown reasons, 71 use an “-et-“, 81 and 91 use a dash.

• 71 = 60 + 11 = “soixante-et-onze”
• 81 = 4 * 20 + 1 = “quatre-vingt-un”
• 91 = 4 * 20 + 11 = “quatre-vingt-onze”

100 and more

One hundred is “cent”. One thousand is “mille”. The rule is joining this and the rest with a dash:

• 130 = 100 + 30 = “cent-trente”
• 1110 = 1000 + 1000 + 10 = “mille-cent-dix”

plurals of “cent” and “mille:

Like 80, 100 and 1000 can be plural if it ends a word and then takes an S: “cents”, “milles”

• 200 = 2 * 100 = “deux-cents”
• 3 000 = 3 * 1000 = “trois-milles”

When “cent” or “mille” is not ending the word, then it is not plural:

• 252 = 2 * 100 + 52 = “deux-cent-cinquante-deux”
• 2045 = 2 * 1000 + 45 = “deux-mille-quarante-cinq”
• 200000 = 2 * 100 * 1000 = “deux-cent-milles”, without S at “cents”, but with S at “milles”
• 180000 = (100 + 4 * 20) * 1000 = “cent-quatre-vingt-milles”, without S at “vingt”, but with S at “milles”

Github Repository

https://github.com/fjobeir/french-numbers-to-words

npm i french-numbers-to-words