Follow the guidelines below in deciding whether to use a hyphen in a fraction written in words.
Fractions used as adjectives
As a rule, hyphenate fractions used as adjectives and written in full:
- a one-third share
- a three-fifths majority
Fractions used as nouns
Usage is divided on whether fractions used as nouns should be hyphenated. Some style guides prefer to omit the hyphen in such fractions:
- Four fifths of the load was wheat, and one fifth barley.
However, the traditional practice (and the one still recommended in most style guides) is to hyphenate fractions whether they are used as adjectives or as nouns:
- Four-fifths of the load was wheat, and one-fifth barley.
When either the numerator or the denominator is a number that already contains a hyphen, do not add a second hyphen:
- twenty-nine hundredths (not twenty-nine-hundredths)
- one thirty-second (not one-thirty-second)
Copyright notice for Writing Tips Plus
© His Majesty the King in Right of Canada, represented by the Minister of Public Services and Procurement
A tool created and made available online by the Translation Bureau, Public Services and Procurement Canada
Search by related themes
Want to learn more about a theme discussed on this page? Click on a link below to see all the pages on the Language Portal of Canada that relate to the theme you selected. The search results will be displayed in Language Navigator.