French Number Converter

How to Use the French Number Converter

1. 1. Enter a number. Whole numbers up to 24 digits work, and so do negatives and decimals. Spaces, points and commas between digit groups are fine.
2. 2. Choose cardinal or ordinal. Cardinals count (trois, quatre-vingts); ordinals rank (troisième, quatre-vingtième).
3. 3. Pick the regional form and the spelling. France and Canada say soixante-dix, quatre-vingts and quatre-vingt-dix; Belgium says septante and nonante; parts of French-speaking Switzerland also say huitante. Choose the traditional spacing or the 1990 hyphens.
4. 4. Say whether the noun is masculine or feminine. A final un becomes une before a feminine noun. Read the result, the other spellings, and the short notes on the rules that applied.

How French Builds Its Numbers

Zero to sixteen are single words: zéro, un, deux … seize. Seventeen to nineteen add a unit to dix (dix-sept, dix-huit, dix-neuf), and the tens from vingt to soixante are regular. The unit 1 is joined to 21, 31, 41, 51, 61 and 71 with et — vingt et un, soixante et onze — but not to 81, 91 or any number after a hundred: quatre-vingt-un, quatre-vingt-onze, cent un.

Standard French in France counts 70 to 99 in twenties: soixante-dix is sixty-ten, quatre-vingts is four twenties, and quatre-vingt-dix-neuf is four twenties and nineteen. Belgium, and Switzerland's French-speaking cantons, use the regular forms septante and nonante. Vaud, Valais and Fribourg also say huitante for 80, while Geneva, Neuchâtel and Jura keep quatre-vingts, so usage inside Switzerland varies. The tool lists the other regions' spelling under every result that differs.

When Vingt and Cent Take an S

Vingt and cent take a plural s only when they are multiplied and nothing follows them. That gives quatre-vingts and deux cents, but quatre-vingt-un and deux cent un: the moment another number follows, the s disappears. The same applies before mille, which counts as a number: quatre-vingt mille, deux cent mille. Million and milliard are nouns, so the s comes back before them — quatre-vingts millions, deux cents millions. Mille itself never takes an s: trois mille. (The plural milles is the unit mile, as in milles marins.)

The 1990 Hyphens

The 1990 spelling rectifications, published in the Journal officiel and summarised by the Académie française, join every numeral of a complex number with hyphens, including those above a hundred and those with et: vingt-et-un, soixante-et-onze, mille-six-cent-trente-cinq. Million, milliard and millier are nouns and stay apart, so 1 200 000 is un million deux-cent-mille. The Académie describes the new spellings as admitted beside the traditional ones, not imposed, and both are correct. The reform changes only the hyphens: the rules for vingt and cent above stay as they were. The converter shows the other spelling under any result where it differs.

Un or Une, and the Long Scale

A final 1 agrees with the noun it counts: vingt et un livres, vingt et une maisons, cent une pages. Before mille, million and the larger names the number stays un, because it agrees with that word and not with the noun that follows: vingt et un mille personnes. French writers hesitate over a feminine noun after mille; the tool writes un there.

French counts in the long scale. A milliard is a thousand million (10⁹); a billion is a million million (10¹²); a billiard is 10¹⁵; and trillion and trilliard are 10¹⁸ and 10²¹. A French billion is therefore not an English billion. A round million or more takes de before a noun — un million d’euros — but not when other numbers follow: un million deux cent mille euros.

Ordinals

Ordinals add -ième to the cardinal: quatre becomes quatrième, vingt becomes vingtième, and a final e drops. Two spellings change: cinq becomes cinquième and neuf becomes neuvième. The final s of quatre-vingts and deux cents falls away (quatre-vingtième, deux centième). Only premier and première (first) are irregular, with unième appearing only at the end of a compound: vingt et unième. For 2 you can choose second or seconde, used traditionally when there are only two; deuxième is always correct. The usual abbreviations are 1er and 1re for first and 2e, 3e and so on for the rest.

Frequently Asked Questions

Why is 80 quatre-vingts in French?

Standard French in France keeps an older habit of counting in twenties: quatre-vingts is four twenties, and 97 is four twenties and seventeen. Belgium and the Swiss cantons that say septante and nonante use regular tens, and Vaud, Valais and Fribourg also say huitante for 80.

Is it quatre-vingts or quatre-vingt?

Quatre-vingts with an s when it stands alone, and quatre-vingt without an s when another number follows it: quatre-vingt-un, quatre-vingt-dix-neuf, quatre-vingt mille. Before million and milliard the s returns, because those words are nouns: quatre-vingts millions.

Is it deux cents or deux cent?

Deux cents when nothing follows, deux cent when something does: deux cent un, deux cent mille. The rule treats mille as a number, so cent loses its s before it. Before the nouns million and milliard the s stays: deux cents millions.

Is it vingt et un or vingt-et-un?

Both are correct. Vingt et un is the traditional spelling; vingt-et-un is the 1990 rectified spelling, which joins every part of a complex number with hyphens. Choose one and use it consistently in a document.

How do you say a billion in French?

A thousand million is un milliard. French uses the long scale, so un billion means a million million (10¹²), which is not the English billion. Translators need to watch this, as a literal “billion” in either direction is off by a factor of a thousand.

Is mille ever plural?

No. Mille is invariable: trois mille, vingt mille. The form milles exists only for the distance unit, as in milles marins (nautical miles). Mil is an older variant of mille that survives in some dates.

How do I read a decimal like 3,14 in French?

As trois virgule quatorze, or digit by digit, trois virgule un quatre. This tool reads the decimals digit by digit, which is unambiguous, and writes a zero as zéro: 0,05 is zéro virgule zéro cinq.