Numbers in Spanish: How to form and write them?

Cardinal numbers in Spanish can be used for much more than counting. You can use them for prices, dates and years, the hour, age, statistics (including percentages), measurements, weight, and distance:

Check out this table with more uses of cardinal numbers in Spanish and examples.

When writing numbers, commas are used to separate the integer from the decimals. The use of the decimal point, typical of the English language, is also accepted in some varieties of Spanish:

To separate thousands, Spanish uses a period or simply a space instead of a comma:

• Uno vs. un and una

  When we use the numbers uno and una (meaning one) or numbers ending in -uno and -una we need to consider gender agreement. Consider the following rules:

  1. Numbers that end in -uno (like 21, 31, and so on) drop the -o when followed by a masculine noun:

     Miguel tiene veintiún años.

     Translation: Miguel is twenty-one years old.

     Note that we dropped the -o from the number veintiuno (meaning twenty-one) but we also added an accent mark to the last vowel.

  2. A number ending in -uno doesn’t change to -un if there’s no noun that follows:

     ¿Cuántos niños hay en la sala? – Veintiuno.

     Translation: How many children are there in the classroom? - Twenty-one.

     But, if we add a noun, then we need to apply rule one above:

     ¿Cuántos niños hay en la sala? – Veintiún niños.

     Translation: How many children are there in the classroom? - Twenty-one children.

  3. Numbers ending in -uno or -una agree in gender with the following noun:

     Treinta y un hombres

     Translation: Thirty-one men
     Treinta y una mujeres

     Translation: Thirty-one women

• Use of conjunction y

  Different from English, in Spanish we use the conjunction y (meaning and) only to separate tens and ones:

  Hay cincuenta y dos personas en línea.

  Translation: There are fifty-two people online.

  Ella nació en mil novecientos setenta y siete.

  Translation: She was born in nineteen seventy-seven.

• Numbers that are written in one word

  In Spanish, some numbers are written in one word only. Numbers from 0 to 30 follow this rule, as do integer multiples of 10 and integer multiples of 100:

  Juanita tiene veintitrés años.

  Translation: Juanita is twenty-three years old.

  Este teatro tiene capacidad para doscientas personas.

  Translation: This theater has a capacity of two hundred people.

  Check out the full list of Spanish numbers written in one word here.

• Gender agreement with compounds of ciento

  Gender agreement is also applicable to compounds of ciento (meaning one hundred). Compare:

  Quinientos kilos

  Translation: Five hundred kilos

  Quinientas libras

  Translation: Five hundred pounds

• Cien vs. Ciento

  The word cien refers to the number “one hundred.” We can use this word before a noun and before other numbers such as: mil, millón, billón, trillón etc.

  Cien personas postularon a la beca.

  Translation: One hundred people applied for the scholarship.

  El proyecto tendrá un costo de cien mil millones.

  Translation: The project will have a cost of one hundred billion.

  The word ciento also refers to the number “one hundred,” but it’s used with numbers from 101 to 199:

  Hay ciento treinta y cuatro personas interesadas en el curso.

  Translation: There are one hundred and thirty-four people interested in the course.
• Millón, billón, and trillón

  Millón refers to the word “million” in English. When saying “one million,” remember to follow the indefinite article rule: drop the -o in uno, like this:

  Uno millón.

  Translation: One million.

  When you add a noun after the number, you need to add the preposition de (meaning of):

  Un millón de personas vieron el partido.

  Translation: One million people watched the game.

In Spanish, ordinal numbers from one to 10 are common in everyday language. After 10, the ordinal versions tend to be replaced by the cardinal numbers:

If you’re not sure that you know ordinal numbers in Spanish, we’ve got you covered with this list.

Just as with cardinal numbers, there are some special considerations with ordinal numbers in Spanish:

• They agree in gender and number with the noun they modify and they are typically placed before the noun:

  Vivo en el segundo piso.

  Translation: I live on the second floor.
  Vivo en la segunda house.

  Translation: I live on the second floor.

• The ordinal numbers primero (meaning first) and tercero (meaning third) drop the final -o before a masculine singular noun and become primer and tercer:

  ¿Cuál es tu edificio? - El tercero.

  Translation: Which is your building? - The third one.
  ¿Cuál es tu edificio? - El tercer edificio.

  Translation: Which is your building? - The third building.

• When you have cardinal and ordinal numbers together in the same sentence, cardinal numbers go first:

  ¿Tienes las tres primeras respuestas?

  Translation: Do you have the first three answers?

• With proper names ordinal numbers go after the noun:

  Carlos V (quinto)

  Translation: Charles V (the fifth)

If you want to review the position of adjectives in Spanish (including ordinal numbers), check out this post.

This covers the basics, but numbers can also be expressed in fractions and multiplicatives. In Spanish, they are very interesting since they can be used as nouns or adjectives. To know more about this, check out “How to use fractions and multiplicatives in Spanish?”