Cardinal Numbers 100+

Above 100, Portuguese cardinals get more interesting. Three new things start happening that didn't apply in the 1-99 range. First, the hundreds (200-900) start agreeing in gender — duzentos and duzentas, quinhentos and quinhentas — even though the units and tens did not. Second, the rules for placing e (and) become subtler when you cross the mil and milhão boundaries. Third, the meaning of bilião depends on whether you're reading conservative PT-PT (long scale: 10¹²) or modern internationalist PT-PT (short scale: 10⁹). This page works through every layer — from 101 up to a billion and beyond — and shows you exactly when to use cem vs cento, when to write e and when to omit it, and how to read large numbers aloud.

For numbers 1-100, see Cardinal Numbers 1-100.

The hundreds: 100 to 900

100 itself: cem vs cento

Both forms exist, distributed by what follows.

• cem alone, or directly before a noun, or before mil/milhão/milhões.
• cento before another number from 1 to 99.

Cem is invariable — no feminine form, no plural. Cem mulheres, cem homens, identical.

200 to 900: the hundreds AGREE in gender

This is the big change at 200. The hundreds from 200 to 900 are adjectival in form and agree in gender with the noun they count, just like dois/duas did. They are always plural in form (since by definition they refer to more than one).

The agreement is strict: quinhentos euros (m) and quinhentas pessoas (f). Forgetting it is one of the most visible A2 errors. The rule applies even when there are intervening words: quinhentas mil pessoas (the quinhentas still agrees with pessoas, even though mil sits between them).

Two awkward shapes worth flagging

• quinhentos (500) is irregular in shape — not cincocentos. It comes from Latin quinquaginta-centi via opaque medieval evolution.
• seiscentos (600) keeps the diphthong ei of seis but is pronounced /ˌsɐjʃˈsẽtuʃ/ in careful speech, with the two s sounds merging in fast speech.

Hundreds + smaller number: e between elements

When a hundred is followed by tens, units, or both, insert e between the hundred and what follows.

Note the agreement carries to the unit at the end: duzentas e vinte e uma alunas (221 female students).

Thousands

mil — invariable as a numeral

Mil is the cardinal for 1000. It is invariable as a numeral — no plural, no gender form, no article when used as a number.

You do not say um mil — just mil. (You do say um milhão, but not um mil.)

Multiplied thousands: the multiplier agrees, mil doesn't

When you have a multiple of a thousand, the multiplier (the cardinal in front) follows its own agreement rules: dois mil, três mil, ..., dez mil, vinte mil, ..., cem mil, duzentos mil, .... The multiplier agrees with the noun's gender, but mil itself stays invariable.

The agreement rule looks past mil to the noun: duzentas mil pessoas, even though duzentas and pessoas are separated by mil.

When to use e with thousands

This is the rule learners most often get wrong. The conjunction e is inserted before the last significant element within the thousands portion of a number. The detailed rules:

Rule 1: Insert e between mil and what follows ONLY when there is no further significant element below 100, OR when the number ends in tens or units alone.

Rule 2: When the number AFTER mil contains a hundred AND smaller elements, the e falls between the hundreds and the smaller elements, NOT after mil.

The principle: e is the last connector before the smallest element. If the smallest element is the hundred (no following tens or units), e goes before the hundred (mil e duzentos). If the smallest element is the tens or units (with hundreds present), e goes there (mil duzentos e trinta).

milhares — thousands as a noun

When mil is used as a noun meaning "thousands of" (in the vague approximative sense), it pluralises as milhares and takes the preposition de.

This is a different word-class from the cardinal mil. As a cardinal, mil is invariable: mil pessoas (one thousand people, exact). As a noun, milhares is plural and counts vaguely: milhares de pessoas (thousands of people, approximate or large).

Millions

um milhão — a noun, takes de

Milhão (and bilião, trilião etc.) is a masculine noun, not a numeral. It carries an article and takes the preposition de before the counted noun.

The de is mandatory. Um milhão habitantes (without de) is ungrammatical.

When de is omitted: with another number after milhão

The de is dropped when the milhão is followed by another cardinal element (a number that further specifies the quantity). The number then continues directly.

The de returns only at the very end if the noun is the final element: um milhão e meio de pessoas (one and a half million people).

Reading a real large number

Take the number 1,234,567. Read aloud it is:

um milhão duzentos e trinta e quatro mil quinhentos e sessenta e sete

Breaking that down:

• um milhão (1,000,000)
• duzentos e trinta e quatro mil (234,000) — note no e between milhão and duzentos
• quinhentos e sessenta e sete (567) — note no e between mil and quinhentos

The pattern: e connects each scale's smallest element to its larger neighbour. Between scales (million / thousand / hundred), there is no e — they sit next to each other in apposition.

Billions and beyond — the long-scale trap

Here the PT-PT vs PT-BR split becomes economically significant.

The traditional PT-PT long scale

In traditional PT-PT (still the school standard, still the conservative norm), numbers above a million follow the long scale:

So in traditional PT-PT:

• English "billion" (10⁹) = mil milhões (a thousand million)
• English "trillion" (10¹²) = um bilião (a million million)

That last example exposes the trap. To clarify properly:

• 10⁹ in English = mil milhões in traditional PT-PT
• 10¹² in English = um bilião in traditional PT-PT

So if a Portuguese journal reports um bilião de euros in the traditional sense, that is 10¹² euros, equivalent to an English trillion — not an English billion.

The modern PT-PT short-scale drift

Under the influence of American English, EU statistical conventions, and PT-BR, modern PT-PT journalism increasingly uses bilião in the short-scale sense (10⁹), matching English billion. You will see this in newspapers like Público and Expresso, in EU documents translated into PT, and in tech and finance journalism.

This creates ambiguity. The same word bilião in two different texts can mean either 10⁹ or 10¹² depending on which scale the writer follows. Always check the digits if precision matters.

PT-BR: short scale throughout

PT-BR follows the short scale consistently: bilhão (note the h) = 10⁹, trilhão = 10¹². This matches modern English usage and is unambiguous within the PT-BR community.

The PT-BR spelling bilhão with -lh- is itself a marker of variety: in PT-PT it is bilião with -li-. So um bilhão de reais is unmistakably PT-BR and means 10⁹; um bilião de euros could be either 10⁹ (modern PT-PT) or 10¹² (traditional PT-PT) depending on the writer.

Trillions and beyond

In conservative PT-PT: trilião (10¹⁸), quatrilião (10²⁴), quintilião (10³⁰). These appear almost exclusively in scientific and astronomical writing; in everyday speech they are rare.

Number formatting: the comma and the period

PT-PT uses the opposite convention from English for separators.

Modern PT-PT (especially EU-aligned and scientific contexts) increasingly uses a non-breaking space instead of the period as the thousands separator: 1 000 000 rather than 1.000.000. Both are acceptable. Smaller numbers (under 10,000) are often written without any thousands separator at all: 1500, 9999.

Reading large numbers aloud: practice

A few realistic sentences:

Common mistakes

Summary tables

Hundreds, masculine and feminine

Larger units

Key takeaways

• Cem is used alone or before a noun (cem alunos, cem mil); cento is used before another smaller number (cento e vinte, cento e cinquenta e três).
• The hundreds 200-900 agree in gender: duzentos / duzentas, quinhentos / quinhentas, novecentos / novecentas. The agreement is strict and mandatory.
• Mil is invariable as a numeral and takes no article. Mil pessoas (not um mil pessoas).
• The multiplier of mil agrees with the noun's gender across mil: duzentas mil pessoas, trezentos mil habitantes.
• The conjunction e falls before the smallest significant element: mil e cem (no further tens), mil duzentos e trinta (with tens after the hundred).
• Milhão is a masculine noun. It takes the article um and the preposition de before the counted noun: um milhão de habitantes.
• Beware the long-scale trap: traditional PT-PT bilião = 10¹² (English trillion). For English billion (10⁹), the safe PT-PT term is mil milhões. Modern PT-PT journalism sometimes uses bilião for 10⁹ under English influence, but the term is ambiguous without context.
• Number formatting: PT-PT uses the comma as decimal separator and the period (or non-breaking space) as thousands separator. The English convention is exactly reversed.