Spanish Numbers 1-100 and Beyond: How to Count Them

The classic beginner slip: you learn cien for 100, then say cien uno for 101. It's actually ciento uno — Spanish keeps cien only when it stands alone or right before a noun, and switches to ciento the moment you add anything after it. Numbers in Spanish are wonderfully regular once you see the patterns, but a handful of traps (accents, one-word spellings, and irregular hundreds) trip up almost everyone. This guide walks you through 1 to 100 in Spanish and well beyond, with every number spelled out and the rules that let you build any number you need.

The short version: Learn 0-15 as unique words, then follow the patterns: dieciséis-diecinueve and veintiuno-veintinueve are written as one word; from 30 up you use treinta y uno with a spelled-out "y". Say cien alone but ciento uno for 101, mil for 1,000 (never "un mil"), and un millón de with a "de".

Numbers 0 to 20: the ones you memorize

There's no shortcut for the first stretch — these words are the building blocks for everything else, so learn them cold. Notice that 16 to 20 already start the compound patterns you'll reuse later.

16 to 29: written as one word

Here's where English speakers hesitate. From 16 to 29, Spanish contracts everything into a single word, and a few of them carry a written accent. Don't write "diez y seis" — it's dieciséis, and the accent is not optional. The teens are built on dieci- and the twenties on veinti-.

The accented ones are dieciséis, veintidós, veintitrés, and veintiséis. These accents fall on the last syllable because the words end in -s and are stressed there — leaving them off is a genuine spelling error, not a typo Spanish speakers forgive.

30 to 100: the "y" pattern

Starting at 30, Spanish stops fusing words and instead links the tens and units with a separate y ("and"). So 31 is treinta y uno, 45 is cuarenta y cinco, 99 is noventa y nueve. The round tens are the only new vocabulary you need — and once you know them, you can count all the way from 1 to 100 in Spanish.

Note the split: 16-29 are one word (veintiséis), but 31-99 are three words with a spelled "y" (treinta y seis). This is the single most common structural mistake beginners make — mixing the two systems. And there's no y before the tens themselves: 40 is cuarenta, not "y cuarenta"; the y only ever sits between a ten and a unit.

The uno / un / una trap

The word for "one" changes shape depending on what follows it. On its own it's uno. Before a masculine noun it drops the -o and becomes un: un libro (one book). Before a feminine noun it becomes una: una mesa (one table).

This carries all the way up. Twenty-one books is veintiún libros — and yes, that shortened form takes a written accent (veintiún). Twenty-one years is veintiún años. Thirty-one books is treinta y un libros. For feminine nouns: veintiuna casas, treinta y una casas.

Quick rule: "one" is un before masculine nouns, una before feminine nouns, and uno when it stands alone (counting, or answering "how many?").

100 and the hundreds: cien vs ciento

One hundred is cien — but only when it's exactly 100, or when it comes directly before a noun: cien euros, cien casas. The moment you add units on top, it becomes ciento: 101 is ciento uno, 150 is ciento cincuenta, 199 is ciento noventa y nueve. And there's no "y" between the hundred and the rest — it's ciento cincuenta, never "ciento y cincuenta".

From 200 up, the hundreds have their own words, and four of them are irregular enough to memorize on their own.

The three to burn into memory are quinientos (500), setecientos (700), and novecientos (900) — they don't follow the "root number + cientos" logic that 200, 300, 600, and 800 do. And the hundreds agree in gender: doscientas casas, quinientas personas, novecientas páginas when the noun is feminine.

Thousands and millions

One thousand is simply mil — and you never say "un mil". It's mil, dos mil, tres mil, and so on. The word mil also doesn't change for plural inside a number: 5,000 is cinco mil, not "cinco miles".

Millions behave differently: here you do say un millón, and when a noun follows, you insert de: un millón de euros, dos millones de habitantes. That de disappears only when other numbers come between: un millón doscientos mil euros. One quick habit to unlearn: Spanish traditionally uses a period as the thousands separator and a comma for decimals, so what English writes as 1,000 you'll often see written as 1.000.

Numbers in real life: age, phone numbers, and prices

Rules stick faster when you hear them in real sentences. Here's how numbers show up in the three situations you'll meet first.

Age. Spanish uses the verb tener ("to have"), not "to be": Tengo veintiocho años (I'm 28). Mi hija tiene un año (My daughter is one year old). Mi abuelo tiene noventa y un años (My grandfather is 91) — note noventa y un años, with the shortened un before the masculine noun años.

Phone numbers. These are usually read in pairs: a number like 645 12 30 88 comes out as seis, cuarenta y cinco, doce, treinta, ochenta y ocho. You can also read each digit one by one, but grouping in twos is the everyday way.

Prices. Cuesta trece euros (It costs 13 euros). El billete cuesta ciento veinte euros (The ticket costs 120 euros). Son ciento uno con cincuenta — 101.50 in a shop, where con introduces the cents. Notice ciento veinte and ciento uno both use ciento, because a number follows the hundred.

Ordinal numbers: first, second, third

Ordinals (first, second…) are a separate set. In everyday Spanish they're mostly used up to tenth; beyond that, people often just use cardinal numbers.

Two of these shorten before a masculine noun, exactly like uno did: primero becomes primer and tercero becomes tercer. So it's el primer día (the first day) and el tercer piso (the third floor), but la primera vez (the first time) stays full because the noun is feminine. Ordinals also agree in gender and number like any adjective: la segunda puerta, los primeros días.

Frequently asked questions

How do you say 100 in Spanish?

One hundred is cien when it stands alone or comes directly before a noun: cien, cien euros, cien personas. It changes to ciento only when you add smaller numbers after it, as in ciento uno (101) or ciento cincuenta (150).

What is 101 in Spanish?

101 is ciento uno. A common beginner mistake is to say "cien uno," but cien becomes ciento the moment any number follows it, and there is no "y" in between. Before a masculine noun it shortens: ciento un libros; before a feminine noun, ciento una casas.

How do you count from 1 to 100 in Spanish?

Memorize 0-15 as unique words, then learn the compound patterns. From 16 to 29 the numbers are written as one word (dieciséis, veintiuno). From 30 to 99 you combine a round ten with a unit using y: treinta y uno, cuarenta y cinco, noventa y nueve. Then 100 is cien. The round tens you need are treinta, cuarenta, cincuenta, sesenta, setenta, ochenta, noventa.

Is it cien or ciento?

Use cien for exactly one hundred and directly before a noun (cien euros). Use ciento when units follow, as in ciento uno (101) or ciento cincuenta (150). There is never a "y" between the hundred and the rest of the number.

How do you write 21 in Spanish?

21 is veintiuno, written as a single word and with no written accent. When it comes before a noun it changes: veintiún libros (21 books, masculine, and here it does take a written accent on veintiún) and veintiuna casas (21 houses, feminine). Don't write it as three words like the 30s and up — the twenties are always one word.

Do Spanish numbers change for gender?

Most don't, but two groups do. "One" and numbers ending in one become una/veintiuna/treinta y una before feminine nouns, and the hundreds agree too: doscientas casas, quinientas personas. Everything in between, like tres or cuarenta, stays the same for both genders.