The en dash or en rule (–) is about the width of the letter n. An en dash is used:
- for parenthetical information (ie instead of commas, round brackets or an em dash) – the en dash is shorter than the em dash, and the space on either side allows the text to reflow more easily to suit screens of different sizes:
The results of the experiment – which were circulated to all laboratories – were very interesting.
Several countries have policies that address this issue – for example, India, New Zealand and the United Kingdom.
- to indicate a number range (but not if the range is preceded by from or between)
10–20 kg but from 10 to 20 kg or between 10 and 20 kg
pages 650–657
- to indicate a date range (but not if the range is preceded by from or between)
1995–96 2012–13 [do not repeat ‘19’ or ‘20’ in the second element, but, for ranges that cross centuries, use the form 1995–2001]
When a span of dates includes 2 different months, a spaced en dash is sometimes used to indicate the range, but avoid this if possible by using the word to to show the range:
1 July 2013 – 25 August 2013 1 July 2013 to 25 August 2013
- to indicate an equal relationship between 2 words; in this case, the en dash means ‘to’ or ‘and’.
Sydney–Canberra rail link
Murray–Darling Basin
Burdekin–Fitzroy River
gas–liquid chromatography
cost–benefit analysis
- to connect names in terms credited to more than 1 author (or inventor, etc)
Creutzfeldt–Jacob disease
Michaelis–Menten constant
Caution! In double-barrelled personal names that are hyphenated, be careful to use a hyphen rather than an en dash (eg Anne-Marie, John Smith-Atkinson).
- to represent chemical bonds (see Chemical bonds)
- as a minus symbol if a mathematical minus symbol is not available or if the symbol is needed infrequently (see Negative numbers)
- for a list within a list (see Lists).
Word processing tip
How to insert an en dash
In Windows (eg Microsoft Word), use Ctrl+- on the numerical keypad; use Alt+0150 on the numerical keypad; or insert from the symbol set (special characters). On a Mac, use Option+-. Word can also be set up to convert 2 hyphens (--) to an en dash (–) using the autocorrect options.
