Words or numerals

The most contentious style question for numbers is whether to spell them out in words or use numerals in body text. The ASG supports the contemporary shift towards numerals, as growing evidence shows they are easier to read. Here are some guidelines you can follow.

Numbers below a million
Generally use numerals for all numbers below a million
The team has completed 6 major projects.
Forecast profits are up by 12%.
The exhibition had 546,340 visitors.

Traditionally, Australian style guides have recommended spelling out numbers ‘one’ to ‘nine’ and then moving to numerals from 10 and above.

This approach sought to strike a balance between clarity and efficiency. It is certainly quicker to write ‘99’ than ‘ninety-nine’, but it was considered safer to write ‘nine’ in body text because ‘9’ as a single character could be lost when reading.

More recently, the evidence has strengthened that numerals are actually easier to read than words. This is partly because they stand out more than was traditionally expected – particularly on screens. More importantly, numerals are easier for readers to process mentally than words, so they are more effective for a wider range of readers and reading skills.

The ASG supports the shift that has been taking place towards the use of numerals over words in body text, although we recognise for many writers and editors this represents a significant change in practice.

Bear in mind that a century ago, it was common advice to spell out numerals up to ‘ninety-nine’, which the Chicago Manual of Style still recommends. The world of business and government has already transitioned to numerals from 10 upward, and is now making the further move to numerals under that in most situations.

The organisation recruited 3 new staff last quarter.
The trip should take around 5 minutes on the tram.
One and zero
Use your judgement with these numbers
Our team is truly one of a kind.
Let’s zero in on any anomalies in the statistics.

Although the general shift in style is toward numerals, you will need to exercise some judgement with ‘1’ and ‘0’. There remains a risk that these numerals could be misread as the letters ‘l’ or ‘O’, depending on the font and context. As always, be consistent if you decide to spell out these numbers in the same text.

But definitely prefer to use numerals for the number 1 in:

Quantities and other measurements

  1 question

  1 km

Times  1 pm
Compound adjectives
  1-day workshop
Comparative and parallel numbers
  We expected 10 people but 1 was ill.

‘One’ and ‘zero’ also appear in some common expressions or idioms that would look odd with a numeral. Spell out the numbers in these cases:

  one day soon

  on the one hand

  one of a kind

  one of those things

  zero in

  zero to hero

Other exceptions
Spell out numbers in these special cases
Two delegates came from overseas.
We have trained thousands of people.

The ASG also recommends spelling out numbers in the following situations:

Numbers that represent inexact ideas

  There are hundreds of project requirements.

Non-decimal fractions

  Three-quarters of the samples are inadequate.

Consecutive numbers that may be confused

  They opened seven $100,000 term deposits.

Numbers that start sentences

  Twenty-two MPs lost their seats at the last election.

Numbers that start complete sentences in list items

  The report makes several recommendations:

  • Five recommendations specify short term actions to reduce the risks.
  • One recommendation addresses a new gap in the risk management system.
  • The remaining recommendations cover governance and reporting procedures.
Numbers from 1 million
Use numerals for precise figures, but combine them with words for more general references
Net losses totalled $1,523,100.
Over 2 million people are eligible for tax relief.
If you are reporting complex financial data that involves figures in the millions (or higher), you will likely need the precision of exact numerals. This is particularly true, for example, in a company’s financial statements.
The company has paid $5,121,099 in tax in the past 10 years.

If you do not need this level of precision, you may want to round larger numbers to the nearest million or hundred thousand. In this case, use a combination of numerals and words. Although smaller numbers are easier for readers to process as numerals, a very long string may slow them down.

The historic buildings of Western Australia received around 1.6 million visitors last year.
See also:   Cardinal numbers,  Numbers,  Ordinal numbers,  Zero