Cardinal Numbers 100+

This page takes the cardinal-number system from one hundred up to one billion. It introduces three new building blocks — cento (100), mille (1000), un milione (1,000,000) — and the one-word concatenation rule that lets Italian write a number like milleduecentocinquanta (1250) as a single uninterrupted word. It also covers two important irregularities: mille changes to mila in the plural (so duemila, not duemille), and milione and miliardo — unlike all the smaller cardinals — inflect for number and behave like ordinary nouns, taking a space and the preposition di before what they count.

By the end you should be able to write any Italian cardinal up to a billion correctly, read any year aloud, and recognise the difference between Italian's milione (10^6) and miliardo (10^9, "one billion" in American English).

Cento (100): singular only, no plural

Cento is invariable. Whether you have one hundred or nine hundred, the form stays cento — there is no centi or centa in standard Italian. The multiples are written as one word: duecento, trecento, quattrocento, cinquecento, seicento, settecento, ottocento, novecento.

A famous use: centuries in art and history

Italian uses the -cento names as standard labels for centuries. Il Trecento is the 1300s (the 14th century). Il Quattrocento is the 1400s (the 15th century). Il Cinquecento is the 1500s (the 16th century). Il Novecento is the 1900s (the 20th century).

This is a piece of cultural literacy: any educated Italian conversation about art, history, or literature will use Trecento, Quattrocento, Cinquecento, Seicento, Settecento, Ottocento, Novecento without translation. Il Duemila is now the standard term for the 21st century.

Mille (1000) → mila (plural)

Mille is the only cardinal that has a suppletive plural. The singular is mille (one thousand); from two thousand onward, the form changes to -mila (with one -l-, one -a, two final letters where the singular has -lle).

Mille combines with units the same way

Within a compound number, you can have mille followed directly by smaller cardinals — written, of course, as one word.

This concatenation can produce remarkably long single words. Native speakers parse them mentally by finding the mille/mila, the cento, and the tens-and-units boundary, the same way a reader of long German compounds parses one piece at a time.

Milione and miliardo: countable nouns

Now the system breaks. Milione (million) and miliardo (billion = 10^9) are not adjective-like cardinals. They are countable masculine nouns. This means three things:

1. They take an article (or numeral): un milione, due milioni, dieci milioni.
2. They inflect for number: milione (sg.), milioni (pl.); miliardo (sg.), miliardi (pl.).
3. They take di before the thing counted (when no smaller cardinal intervenes): un milione di abitanti, due milioni di euro, dieci miliardi di stelle.

When 'di' drops: with smaller cardinals attached

If a smaller cardinal follows milione or miliardo, you do not use di:

The logic: milione/miliardo is a noun, so it takes di to introduce its complement. But if a smaller cardinal already specifies the rest of the number, the smaller cardinal directly modifies the counted noun, and di is not needed.

The complete model: combining the system

Putting it all together, here is how a complex number like 1,234,567 is built and read in Italian:

• 1,234,567 = un milione duecentotrentaquattromila cinquecentosessantasette
• The structure is: un milione (1 × 10^6) + duecentotrentaquattromila (234 × 10^3) + cinquecentosessantasette (567).
• The second and third parts are written as a single word.
• The first part (un milione) is separated by a space from the rest, because milione is a countable noun.
• No di before the smaller cardinals, because they continue the number.

Years: read as one long word, or in pairs

Until recently, Italian read years exclusively as their full cardinal compound — written as one word. So 1492 was millequattrocentonovantadue (literally one-thousand-four-hundred-ninety-two).

In the last decade, especially in informal speech and on social media, you can hear young Italians say years in pairs the way English does — millequattrocento-novantadue spoken as quattordici-novantadue (fourteen ninety-two). This is a clear influence from English usage and is regarded as informal. In writing, in news broadcasts, and in any neutral-to-formal register, the one-word reading is still the standard.

The article on years

When you talk about a year as a noun (rather than situating an event in time with nel), you use the masculine article il: il 1492 fu un anno di scoperte ("1492 was a year of discoveries"). The article is essential — bare years without an article would feel like a date abbreviation.

Punctuation: opposite of English

We covered this in Numbers Overview, but it bears repeating in the context of large numbers. Italian uses:

• Period (.) as the thousands separator: 1.000, 1.000.000, 1.234.567.
• Comma (,) as the decimal separator: 3,14; 1.250,75.

This is the exact opposite of English-language convention. So an Italian-language price tag of €1.250,00 means one thousand two hundred fifty euros and zero cents, not one euro and twenty-five cents. Being able to read this without hesitation is essential for anyone living in Italy.

Common Mistakes

These are the recurring slips for English speakers handling large Italian numbers.

Key takeaways

1. Cento is invariable. Multiples are written as one word: duecento, trecento, …, novecento. The named centuries (Trecento, Quattrocento, Cinquecento, Novecento) are an essential piece of cultural literacy.

2. Mille becomes mila in the plural. Duemila, tremila, diecimila, centomila. Never duemille.

3. Numbers up to a million are written as one word, with no spaces, no hyphens, and no e (and) between components: milleduecentocinquanta, tremilanovecentonovantacinque, centomilaventitré.

4. Milione and miliardo are nouns. They take an article, inflect (milione/milioni, miliardo/miliardi), and require di before their complement when no smaller cardinal follows: un milione di persone, tre miliardi di stelle.

5. Italian miliardo = English "billion" (10^9). The word bilione exists but is rare and technical; in everyday Italian, un miliardo is what you use for what English speakers call a billion.

6. Years are read as one word: millequattrocentonovantadue, duemilaventicinque. The pair-reading (fourteen ninety-two) is an English-influenced informal innovation; standard Italian still says the full compound.

7. Punctuation is the exact opposite of English. Period as thousands separator (1.000.000), comma as decimal separator (3,14). Misreading this is the most common error English speakers make with Italian numbers.

8. For dates and years specifically, see Dates, which builds on this page to cover the full date system (day-month-year) including the special use of the ordinal primo for the first of the month.