How do I count to 100 in Spanish?

Memorize 1-15 as unique words (uno, dos, tres...quince). 16-29 are compressed compounds (dieciséis, veintiuno). 30+ follow the pattern: tens + y + ones (treinta y uno, cuarenta y cinco, etc.).

When does uno become un?

Uno drops the final o → un before masculine singular nouns. Un libro, veintiún años, treinta y un coches. Una stays unchanged for feminine: una mesa, veintiuna chicas.

What's the difference between cien and ciento?

Use cien when 100 stands alone or before a noun (cien libros). Use ciento when followed by more numbers (ciento veinte = 120). The only exception is por ciento (percent), which always uses ciento.

Do hundreds agree with gender in Spanish?

Yes, from 200 to 900, hundreds agree with the noun's gender. Doscientos hombres / doscientas mujeres. Watch the special forms: quinientos (500), setecientos (700), novecientos (900).

Why does Spanish use commas for decimals?

Spanish convention swaps the use of commas and periods compared to English. Spanish: 1.000 = a thousand, 1,5 = 1.5. English: 1,000 = a thousand, 1.5 = 1.5. Different but consistent within each language.

Spanish grammar · Beginner

Spanish Numbers: 0 to a Million

Written by Sofia Ramirez, Lead Spanish Curriculum Editor · Reviewed May 2026

Spanish numbers (números) follow predictable patterns once you master 1-30 and the basic units (cien, mil, millón). Most are invariable; uno / un / una and the hundreds (doscientos, trescientas) agree with gender.

Tengo veintiuno años.

I'm twenty-one years old.

What it is

Spanish numbers (números) follow predictable patterns once you master 1-30 and the basic units (cien, mil, millón). Most numbers are invariable, but uno / un / una and the hundreds (doscientos / doscientas) agree with gender. Compounds (16-29) merge into single words; 31+ separate with y.

16 = dieciséis (one word). 25 = veinticinco (one word). 31 = treinta y uno (three words with y).

How to spot it

Look for cardinal numbers (uno, dos, tres...) or ordinal numbers (primero, segundo...). Cardinals are far more common in everyday speech.

Tengo veintiún años. — I'm twenty-one years old.
Costó doscientos euros. — It cost two hundred euros.
Hay mil personas. — There are a thousand people.

Spanish uses comma for decimals and period for thousands, opposite of English. 1.000 = 1,000 in English; 1,5 = 1.5 in English.

Spanish Numbers Quick Reference

Spanish numbers, key cardinals

Number	Spanish	Notes
0	cero	-
1-15	uno, dos, tres, cuatro, cinco, seis, siete, ocho, nueve, diez, once, doce, trece, catorce, quince	Memorize as a unit
16-19	dieciséis, diecisiete, dieciocho, diecinueve	diez + y + n contracted
20	veinte	-
21-29	veintiuno, veintidós... veintinueve	veinti- prefix, one word
30-99	treinta, cuarenta... y... uno, dos...	treinta y uno (three words)
100	cien (alone) / ciento (compound)	cien libros / ciento veinte
200-900	doscientos, trescientos... agree with gender	doscientas casas
1,000	mil	Invariable as adjective
1,000,000	un millón (de)	Takes de before noun

Common Spanish Numbers Examples in Spanish

Spanish numbers in real contexts:

Ages and Quantities (1-100)

Tengo veintiún años.: I'm 21.
Hay treinta y cinco estudiantes.: There are 35 students.
Compré cuarenta libros.: I bought 40 books.

Veintiuno drops the final o → veintiún before masculine nouns. Same for treinta y uno → treinta y un.

Hundreds (Agree with Gender)

Doscientos hombres / doscientas mujeres.: 200 men / 200 women.
Quinientas personas.: 500 people.
Setecientos euros.: 700 euros.

Hundreds AGREE with gender of the noun: doscientos coches, doscientas mesas.

Thousands and Millions

Mil personas. Dos mil euros.: 1,000 people. 2,000 euros.
Cien mil libros.: 100,000 books.
Un millón de dólares.: A million dollars.

Mil is invariable (never miles for thousand). Millón takes de before nouns: un millón de dólares.

Spanish Number Punctuation

1.000 = mil (period for thousands): 1,000 = a thousand
1,5 metros = 1.5 metros (comma for decimals): 1.5 meters

Spanish uses comma for decimals and period for thousands, the opposite of English convention.

How Spanish Numbers Work

Memorize 1-30 First

Numbers 1-15 are unique words. 16-29 are diez + y / veinti + n compressed into single words (dieciséis, veintiuno).

Uno, dos, tres... quince. Dieciséis, diecisiete... veinte. Veintiuno, veintidós... veintinueve.

1-15 unique. 16-29 compressed compounds.

From 30 on, the pattern becomes predictable: tens + y + ones (treinta y uno, cuarenta y dos).

Uno → Un / Una Before Nouns

Uno drops the final o → un before masculine singular nouns. Una matches feminine. This apocope applies to 21, 31, etc. too.

Un libro, una mesa. Veintiún años, veintiuna chicas. Treinta y un coches.

A book, a table. 21 years, 21 girls. 31 cars.

Same rule for compounds: 21 = veintiún (before masc. noun) / veintiuna (before fem. noun).

Cien vs. Ciento

Use cien when 100 stands alone or precedes a noun. Use ciento when followed by smaller numbers (101-199).

Cien libros. Cien euros. PERO: Ciento veinte. Ciento cincuenta.

100 books. 100 euros. BUT: 120. 150.

Quick test: is anything after the 100? If yes → ciento. If no → cien.

Hundreds Agree with Gender

From 200 to 900, hundreds AGREE with the gender of the noun.

Doscientos hombres / doscientas mujeres. Quinientos libros / quinientas páginas.

200 men / 200 women. 500 books / 500 pages.

Watch out: 500 = quinientos (not cincocientos), 700 = setecientos (not sietecientos), 900 = novecientos (not nuevecientos).

Millón Takes De

Un millón / dos millones / etc. take de before the noun. Mil does NOT take de.

Un millón de dólares. Dos millones de personas. PERO: Mil personas (no de).

A million dollars. Two million people. A thousand people.

Millón is a noun; mil functions as an adjective.

Common Mistakes with Spanish Numbers

Incorrect: Tengo veintiuno años. — I'm 21 years old. (wrong, uno → un before masc. noun)

Correct: Tengo veintiún años. — I'm 21 years old.

Veintiuno drops final o → veintiún before masculine nouns (años). Same apocope as uno.

Incorrect: Doscientos casas. — 200 houses. (wrong, hundreds agree with gender)

Correct: Doscientas casas. — 200 houses.

Casas is feminine, use doscientas. Hundreds (200-900) match the noun's gender.

Incorrect: Un millón dólares. — A million dollars. (wrong, missing de)

Correct: Un millón de dólares. — A million dollars.

Millón requires de before the noun. Un millón de + noun. Mil does not need de.

Uno / Un / Una Apocope

Uno Drops the O Before Masculine Nouns

Uno → un before masculine singular nouns. Una stays as una for feminine. Same rule applies to compound numbers ending in uno (21, 31, 41, etc.).

Un libro. Una mesa.: One book. One table.
Veintiún años. Veintiuna chicas.: 21 years. 21 girls.
Treinta y un coches. Cuarenta y una casas.: 31 cars. 41 houses.

Even more than 1 million: A million is un millón, uno → un applies in compound thousands too.