Numbers in Spanish

The default starting block is uno, dos, tres, cuatro, cinco, seis, siete, ocho, nueve, diez. From there the system is mostly regular, with irregulars in the teens (once, doce, trece, catorce, quince), a contracted block at 16-19 and 21-29 (dieciséis, veintidós), a switch to three-word numbers at 31 (treinta y uno), and two irregular hundreds the textbooks bury (quinientos, setecientos). This article covers cero to un millón, the y rule, the cien vs ciento split, gender agreement, ordinals, and the regional pronunciation split.

0 to 10

Zero is cero, not the English "zero" with the z sound. The c here is th in Spain and s in Latin America; the same split applies to every c-before-e-or-i and every z in the system.

11 to 20

The teens split in two. Once, doce, trece, catorce, quince are irregular: memorise them. Dieciséis, diecisiete, dieciocho, diecinueve are contracted from diez y seis, diez y siete, and so on. The contraction is now mandatory in writing.

The written accent on dieciséis is not optional: the contraction shifts the stress to the final syllable and the accent marks it. Same logic applies to veintidós, veintitrés and veintiséis in the next block.

20 to 99: the y rule

This is the most productive block in the system. The tens:

The 21-29 block contracts to one word: veintiuno, veintidós, veintitrés, veinticuatro, veinticinco, veintiséis, veintisiete, veintiocho, veintinueve. The accents on veintidós, veintitrés and veintiséis are mandatory.

From 31 onwards the contraction stops and Spanish switches to three words with y (and) in the middle: treinta y uno, cuarenta y dos, cincuenta y tres, sesenta y cuatro, setenta y cinco, ochenta y seis, noventa y siete, noventa y nueve. Once you have the tens and the units, every number from 31 to 99 is mechanical: tens word, y, units word. No accents because the words stay separate.

The cut-off between contracted (21-29) and expanded (31+) is the spelling rule that catches every learner. Textbooks rarely flag it as a single rule, but it is one: 16-19 and 21-29 contract to single words, everything else uses y.

100 and the cien vs ciento split

One hundred is either cien or ciento, and the choice is fixed by what comes next. Cien is exactly 100 standing alone, the form you use immediately before any noun (cien personas, cien euros, cien años), and the form before mil and millones (cien mil, cien millones). Ciento is the form for 101 to 199 (ciento uno, ciento veinte, ciento noventa y nueve).

So 100 euros is cien euros, 150 euros is ciento cincuenta euros, 200 euros is doscientos euros. The split is irregular and the single most reliable register tell once the rest of your Spanish has caught up.

200 to 900: the hundreds

The hundreds are mostly regular (units plus -cientos), but two are irregular and they are the ones learners forget.

Quinientos (not cincocientos) and setecientos (not sietecientos) are the two irregulars. Novecientos feels irregular because the unit is nueve; the c drops the u.

The hundreds agree in gender: before a feminine noun the -os ending shifts to -as. Doscientas casas, trescientas personas, quinientas mujeres, setecientas páginas. Cien itself does not change (cien casas, cien libros); only the 200-900 forms shift.

1,000 and beyond

A thousand is mil with no article: not "un mil." Two thousand is dos mil, ten thousand diez mil, one hundred thousand cien mil. A million takes the article: un millón, dos millones. Above a million the noun being counted needs de: un millón de personas, dos millones de euros. With mil no de is needed: mil personas, dos mil euros.

Punctuation note: Spanish uses a full stop as the thousands separator and a comma as the decimal point, the opposite of English. So 1.500 is one thousand five hundred and 3,14 is three point fourteen.

Uno and gender: the apocope

Uno is the only cardinal that changes before a noun, and it does so for gender. Un before a masculine noun (un libro), una before a feminine noun (una casa), uno standing alone (¿cuántos quieres? uno).

The same shift applies in the compounds: veintiún libros (with a mandatory written accent because the apocope shifts the stress), veintiuna casas, treinta y un libros, treinta y una casas. The 21+ apocope is the most common spelling mistake in adult-learner Spanish; the textbook gives veintiuno and forgets to mention that it becomes veintiún the moment a masculine noun appears.

Ordinals: first to tenth, then mostly cardinals

Ordinals exist in Spanish but get used much less than in English. The first ten are worth learning: primero, segundo, tercero, cuarto, quinto, sexto, séptimo, octavo, noveno, décimo. Feminine forms swap the final o for a: primera, segunda, tercera, and so on.

Primero and tercero apocopate before masculine singular nouns: el primer día, el tercer piso. The full form returns before feminine nouns and in the plural: la primera vez, los primeros días.

Past tenth, Spanish speakers mostly switch to cardinals. The eleventh floor is el piso once, not el undécimo piso (which exists but reads as archaic). Alfonso XIII is read Alfonso trece, not Alfonso decimotercero. Drill the first ten ordinals and use cardinals above that.

Regional pronunciation: the c and z question

The headline regional difference in Spanish numbers is the pronunciation of c (before e or i) and z. In Spain (except the south), these are pronounced like the English unvoiced th in think, so cinco is THIN-ko, doce is DO-the, once is ON-the, quince is KEEN-the, cero is THE-ro. In Latin America (and in Andalusia and the Canary Islands), the same letters are pronounced as s, so cinco is SIN-ko, doce is DO-se, once is ON-se, cero is SE-ro.

The distinction is called distinción in Spain and seseo in Latin America. Neither is more correct. Spanish speakers from one region understand the other effortlessly. Pick the one that matches the variety you are learning. For the wider pronunciation system, see the Spanish alphabet page.

Numbers in real contexts

Prices. Quoted as euros, con, cents. Two euros forty is dos con cuarenta. Twelve eighty is doce con ochenta.

Phone numbers. Said in pairs, not digit by digit. The Madrid number 912 345 678 is read as nueve-doce, treinta y cuatro, cincuenta y seis, setenta y ocho. The hardest context for foreign learners because the pairs come fast and require instant decoding of the 21-99 block.

Addresses. Calle Atocha, número 47 is calle Atocha, número cuarenta y siete. Flat numbers come after: 47, 3º izquierda is cuarenta y siete, tercero izquierda. The ordinal is written with a superscript º (masculine) or ª (feminine).

Times. Hours plus minutes with y (past) or menos (to): son las dos y media (half past two), son las cinco menos diez (ten to five). The hour is plural except for one o'clock: es la una, son las dos. For the price-quoting register, see Spanish phrases for the restaurant.

Cross-links

• The Spanish pillar covers the wider adult-learner approach to Spanish.
• The Spanish alphabet covers the c / z / s pronunciation system that underlies the regional split in cinco and doce.
• The Spanish vocabulary by CEFR article covers the staged curriculum that puts cardinals 1-100 at A1 and the ordinals plus large numbers at A2.
• The how to say good morning in Spanish article covers the time-of-day greetings that pair with the clock-time number patterns above.
• The Spanish phrases for the restaurant article covers the price-quoting register where the 21-99 block and the cien vs ciento split show up most often for travellers.