Fractions

Fractions in Spanish

We use fractions (las fracciones) to refer to parts of a whole. Fractions contain a cardinal number and an ordinal number separated from each other by a line.

We use fractions in mathematics as well as in everyday contexts such as recipes (½ litro de agua).

Learn how to say fractions in Spanish with Lingolia, then practise in the interactive exercises.

Contents

How to write and say fractions in Spanish

Fractions are composed of two elements the numerator (el numerador) and the denominator (el denominador).

The table below shows how to say the most common fractions in Spanish.

Fraction Fraction
1/2 un medio or mitad 1/30 un treintavo or trigésimo
1/3 un tercio 1/40 un cuarentavo or cuadragésimo
1/4 un cuarto 1/50 un cincuentavo or quincuagésimo
1/5 un quinto 1/58 un cincuentaiochoavo
1/6 un sexto 1/60 un sesentavo or sexagésimo
1/7 un séptimo 1/70 un setentavo or septuagésimo
1/8 un octavo 1/80 un ochentavo or octogésimo
1/9 un noveno 1/90 un noventavo or nonagésimo
1/10 un décimo 1/100 un centésimo
1/11 un onceavo or undécimo 1/105 un cientocincoavo
1/12 un doceavo or duodécimo 1/200 un doscientosavo
1/13 un treceavo 1/1.000 un milésimo
1/14 un catorceavo 1/10.000 un diezmilésimo
1/20 un veinteavo or vigésimo 1/100.000 un cienmilésimo
1/21 un veintunavo 1/1.000.000 un millonésimo
1/22 un veintidosavo 1/2.000.000 un dosmillonésimo

Things to know about Spanish fractions

Example:
1/4 → un cuarto
  • The denominator is plural if the numerator is greater than 1.
Example:
3/4 → tres cuartos
  • After fractions, use the preposition de + article (= of the).
Examples:
Nos hemos comido ya 3/4 del bizcocho.We’ve already eaten three quarters of the cake.
Me he leído ya 3/4 de la novela.I’ve already read three quarters of the novel.
  • We don’t use an article with units of measurement.
Example:
1/4 de litro de leche son 250 mililitros.A quarter of a litre of milk is 250 millilitres.
not: 1/4 del litro

mitad or medio (½)

The fraction 1/2 has two different forms.

  • The word medio is used before a noun and it agrees in terms of gender and number.
Examples:
medio litro de aguahalf litre of water
La tortilla lleva media docena de huevos.The tortilla contains half a dozen eggs.

Info

When medio is used before a noun, it stands alone; it is not introduced by un/uno nor is it followed by de.

Examples:
medio litro de agua
not: un medio del litro
media docena de huevos
not: una media de la docena
  • The word mitad is introduced by an article (la/una) and is followed by the preposition de + noun.
Example:
Hemos pagado ya la mitad del préstamo.We’ve already paid half of the loan.
La mitad de la clase está de vacaciones.Half of the class is on holiday.

Denominators from 3 to 10

The number 3 as a denominator is an exception: un tercio.

Example:
1/3 → un tercio

Numbers 4 to 10 as denominators are expressed as ordinal numbers. If the numerator is higher than 1, then the denominator is plural.

Example:
4/6 → cuatro sextos

Denominators from 11

From the number 11, denominators are cardinal numbers with the ending –avo(s).

Example:
1/11 → un onceavo

For tens ending in 0 (20, 30, 40, …), we can also use ordinal numbers.

Example:
1/40 → un cuadragésimo or un cuarentavo

If the denominator is a number made up of two or more words, we write them as one word. The preposition y becomes an i.

Example:
9/99 → nueve noventainuevaovos

In the event that two vowels appear one after another, we only write one.

Examples:
1/30 → un treintavo
not: un treintaavo
5/108 → cinco cientochoavos
not: cinco cientoochovaos

For multiples of ten in the hundreds, thousands, hundred thousands etc. we always use ordinal numbers.

Example:
1/20,000 → un veintemilésimo

Info

Fractions in the hundreds, thousands, hundred thousands etc. are feminine in Spain and masculine certain countries in Latin America.

Examples:
la diferencia de una décima de milímetrothe difference of one tenth of a millimetre (Spain)
la diferencia de un décimo de milímetro (Latin America)