100 Million in French
Cent Millions, with the Plural-S

The Cent-Loses-S Rule

The classical rule for the plural-s on cent is documented in the Dictionnaire de l’Académie française and goes like this. Cent takes a plural-s if it is multiplied by another number AND nothing else follows in the count. So you write deux cents for 200 (multiplied by deux, nothing follows, s appears) and quatre cents for 400. But you write deux cent un for 201 because un follows; the multiplication is no longer the final operation, so the s drops. The same applies to deux cent mille (200,000), trois cent mille, etc. As soon as another counting word appears after cent, the s comes off.

Cent millions follows this rule: millions follows cent, so cent loses its s. The standalone cent form (without prefix multiplier) does not display a plural-s in the first place because there is no multiplication. So cent millions reads as “hundred millions” in literal English: cent quantifies how many groups of one million there are.

For a multiplied form like 200 million, the historical rule said you write deux cents millions (cent takes the s because it is preceded by deux and millions arguably does not count as a counting word for this rule). The 1990 rectifications recommended simplifying this to deux cent millions, dropping the s before millions and milliards. The OQLF Banque de dépannage linguistique notes both forms are acceptable; modern editorial style typically follows the rectified form (no s before million / milliard / billion).

Why Millions Always Keeps Its S

Million is in the noun class, the same grammatical category as milliard, billion, douzaine, centaine. Nouns pluralise the moment they refer to a count greater than one. Five hundred million is cinq cent millions, with millions taking the plural-s because the count is plural, full stop. There is no “another counting word follows” conditional rule for nouns; the conditional rule applies only to determiners.

The same logic is what produces deux mille cinq cents (2,500: cents keeps its s because nothing follows) but deux mille cinq cent un (2,501: cent drops its s because un follows). And deux millions always has the s. And deux mille millions would have mille invariable (mille never pluralises) and millions with the s.

The asymmetry is unusual but it is internally consistent. Determiners (vingt, cent, mille) belong to the number system. Nouns (million, milliard, douzaine) belong to the noun system. They follow their own respective rules.

Worked Examples

Where 100 Million Naturally Appears

Astronomy. The Sun-Earth distance averages cent cinquante millions de kilomètres (one astronomical unit). The Moon orbits at roughly trois cent quatre-vingt mille kilomètres from Earth, so the Sun is about four hundred times further. Mars at perihelion is about cinquante-cinq millions de kilomètres away, swinging out to quatre cents millions de kilomètres at aphelion. Planetary distances from the Sun are conventionally given in millions of kilometres, so the cent-millions form turns up regularly in popular astronomy writing.

Population. The European Union has roughly quatre cent quarante millions d’habitants (440 million inhabitants). The United States has about trois cent quarante millions d’habitants. The figure 100 million serves as a natural unit when discussing continental-scale demographics and is the threshold beyond which a country counts as one of the world’s most populous (currently 14 such countries).

Geological time. The dinosaurs went extinct around soixante-six millions d’années ago, at the K-Pg boundary. The last common ancestor of humans and chimpanzees lived around six millions d’années ago. The Cambrian explosion was around cinq cent quarante millions d’années ago. The unit million-of-years (Ma in scientific notation) is foundational to French popular geology and palaeontology writing.

Cinema and music. A French film grossing cent millions d’euros at the box office (about 110 million USD) is a major commercial success; only a handful of releases hit that threshold each year. A song with cent millions de vues on YouTube enters the territory where it would chart globally. The unit cent millions has natural cultural resonance as the threshold for “global hit”.

Mistakes English Speakers Make at the 100 Million Threshold

Putting an s on cent. Cents millions is wrong (in modern post-1990 orthography). Write cent millions. The s only appears when cent is multiplied AND no counting word follows; here, millions follows.

Dropping the s on millions. Cent million singular is wrong. Million is a noun and pluralises whenever the count is plural. Cent millions always has the s.

Forgetting de before counted nouns. Cent millions habitants is wrong. The number ends with the noun millions, so de is required: cent millions d’habitants.

Comma instead of space for digit grouping. 100,000,000 is the English typographic convention. French uses thin space: 100 000 000. The comma in French is the decimal separator only.

Frequently Asked Questions