How to write one and half years in numbers

Numbers as numerals are generally easier for people to scan. Numbers as words remain a convention that people expect in some types of content.

In text, the general rule is:

• Use numerals for ‘2’ and above.
• Write the numbers ‘zero’ and ‘one’ in words.

Follow the same rule for writing numbers in headings and subheadings. Apply exceptions to this general rule in specific situations, explained on this page.

The numbers ‘0’ and ‘1’ are difficult for some users to read. Some typefaces make it difficult to see the difference between:

• the letter ‘O’ and numeral ‘0’
• the letters ‘I’ (capital ‘i’), ‘l’ (lower-case ‘L’) and numeral ‘1’.

In some typefaces, the numeral ‘1’ can also be confused with the numeral ‘7’.

Writing ‘zero’ and ‘one’ helps to ensure all users understand you are referring to the number.

• Only one person agreed to it.
• Their aim is zero net emissions by 2050.
• They were open to discussing 3 options.

• Only 1 person agreed with it.
• Their aim is 0 net emissions by 2050.
• They were open to discussing three options.

Use words for 2 and above in these specific situations

There are exceptions to the general rule for using numerals in text. 

Use words for numbers when:

• starting a sentence
• writing a fraction
• writing a proper noun that includes a number written as a word
• writing a publication title that includes a number written as a word
• quoting a figure of speech.

In addition, use words for numbers below 10 for government content that follows journalistic conventions (for example, media releases).

Starting a sentence with a number

Start sentences with words rather than numerals. If you must use a number at the start of a sentence, write it out in words.

• Twelve people from our group went to the rally.
• From our group, 12 people went to the rally.

• 12 people from our group went to the rally.

It is sometimes better to rearrange the sentence.

• The board received 621 complaints.

• Six hundred and twenty-one complaints were received by the board.

Fractions

Write words in general text for fractions.

Use fractions when:

• an exact number is not important
• the user needs only a general idea of the values.

If the exact number and value is important, use decimals instead.

• About two-thirds of staff attended last week’s meeting.
• There were 270 candidates for the Legislative Council, an average of 7.5 candidates per vacancy.

Proper nouns, titles of publications and figures of speech

Write numbers as words if this is how they appear in a name or title.

The Treasurer wrote the terms of reference for the Review of the Four Major Banks and Other Financial Institutions.

Private politics : a study of five political outlooks by Alan Davies

Use words for figures of speech.

• Two’s company and three’s a crowd.
• Let’s take five.
• She felt ten feet tall.

Government content and other style conventions

Various style guides treat numbers differently. Media organisations generally use words for all numbers below 10 (or 11), and use numerals for the rest.

Content of the same type necessarily uses the same style, for example, in media releases.

Check your user research. It might show a need to use words for numbers other than ‘zero’ and ‘one’, for example, in:

• longer works
• print publications containing very few numbers.

Be consistent. Once your style for numerals or words is settled, use the same style throughout the content or series of publications. 

Write all numbers as numerals in these specific situations

There are exceptions to using words for ‘zero’ and ‘one’.

Write all numbers as numerals:

• in units of measurement
• to show mathematical relationships – such as equations and ratios – and for decimals
• when you are comparing numbers
• in tables and charts
• for dates and times
• in a series of numbers
• in specific contexts – such as steps, instructions, age and school years
• in scientific content.

Units of measurement

Always use numerals to report a measurement (unless it is a large rounded number).

Mathematical formats, relationships and comparisons

Always use numerals:

• to show mathematical relationships (such as equations and ratios)
• in decimal numbers
• to compare numbers
• in tables, graphs and charts.

Use numerals when writing fractions in specialist content. Otherwise the general rule is words for fractions.

Mathematical relationships

Use well-understood conventions to write mathematical relationships. Keep relationships together so they are easily understood. To do this use:

• numerals only
• the correct operator characters
• spacing between numerals and operators
• non-breaking spaces.

Decimal numbers

Use decimals when you need to be precise. Always write them as numerals.

• They had 8.5 full-time equivalent staff in the section.
• Innisfail averages 3,547.8 mm of rainfall per year.

Comparisons

Compare numerals, not words and numerals. If one number is a decimal, the other must be a decimal and so on.

For those aged 75 to 84, the rate was 2.5 times as high as the rate for the control group. This fell to 1.1 times as high for those aged 85 and over.

For those aged 75 to 84, the rate was over twice as high as the rate for the control group. This fell to 1.1 times as high for those aged 85 and over.

Comparisons are sometimes hard for people, so make them clear. It may seem obvious, but comparisons are only useful if like is compared with like.

Tables, graphs and charts

Lists or blocks of data must consist of numerals, or people will find them hard to understand. Always use numerals in graphs, charts and tables. Numerals save space and help people scan, find and compare values quickly.

Restrict data to key indicators and results. Keep the presentation of data as simple as possible, and use consistent units and magnitudes.

Date and times

Always use numerals for dates and time.

• Wednesday 1 April 2020
• She took the call at 1 pm.

Series of numbers

In any document that contains a lot of numbers, it is always better to write numbers as numerals.

Always use numerals for:

• a related group of items
• a discussion of statistics.

This is regardless of the size of the numbers involved.

The anthology includes 160 poems by 22 poets – 14 of whom were born in Australia, 4 in New Zealand, 3 in England and 1 in Austria.

The number of internet subscribers increased by 3.6%. Fibre connections grew by 22.4% and fibre growth for the year to June was 69.8%.

If you have two series of numbers, for the sake of clarity you can use words for one series and numerals for the other.

Of the mothers of the 23 sets of triplets registered during the year, 8 had no previous children, 8 had one child and 7 had two previous children. 

[The first series uses numerals to break down the total number of triplets according to groups of mothers. The second series uses words for the number of children each group of mothers had already had.]

Lists of steps and instructions

Lists, points and instructions are easier to follow if written as numerals.

• 1. Write a list
• In point 2 of the record of discussion ...
• Step 3: insert the audio cable into the left audio jack.

Age and school years

Always use numerals for age and school years.

• They're a close-knit group of 12 year olds.
• The siblings are in year 1 and year 5.

In scientific content

You can use powers of 10 for large numbers in technical content, such as science and engineering publications. Don’t use powers of 10 in general content.

2.5 × 106 is the same as 2,500,000

Use commas in numbers with 4 or more digits

Numbers from 1,000 need a comma. Separate the digits into groups of 3 (working from right to left).

Don’t use a space or non-breaking space instead of a comma. This is because screen readers can announce spaced digits as separate numbers.

• The government awards 2,500 grants to community projects annually.

• The government awards 2 500 grants to community projects annually.

Combine numerals and words for large rounded numbers

Numbers up to one million are easy to read as numerals. When you’re using rounded numbers of 1,000 or more, use commas to separate numerals into groups of 3 (working right to left). 

Use a combination of numerals and words for large numbers over a million when they are rounded. It is easier to read ‘2.5 million’ than ‘2,500,000’.

• The budget allocated $50 billion to that initiative.
• The organisation announced $3 trillion in superannuation savings.

Billions, trillions and quadrillions:

• billion = 1,000 million (109)
• trillion = million x million (1012)
• quadrillion = thousand x million x million (1015).

Choose between numerals or words for currency

Use numerals and symbols for amounts of money.

• They self-declared a $0 turnover.
• 50c
• $1
• US$20,000.

However, money can be written entirely in words for approximations and figures of speech.

• The government’s new policy will save thousands of dollars.
• That’s my two cents worth.

Release notes

The digital edition updates the rule for using words for numbers in paragraph text.

It recommends using words only for zero and one, and using numerals for other numbers. Government content that follows journalistic conventions is treated as an exception. 

Expert advice has informed this change from the sixth edition. The change reflects accessibility considerations and style for numbers in contemporary digital content.

The sixth edition recommended using words up to 100 (in general text) or words up to 9, and then numerals (in statistically oriented text). The digital edition retains the rule to start a sentence with a word rather than a numeral and lists some other exceptions to the new general rule, consistent with sixth edition guidance.

The digital edition retains the sixth edition rule about using numerals in tables and technical content. It also retains the rules about using words for common expressions and to begin sentences. The sixth edition rule about using a mixture of words and numerals for large numbers also appears in the digital edition.

The Content Guide recommended numerals for all numbers, including zero and one, noting a few exceptions to the rule.

Bohm T (2 December 2019) Letter and symbol misrecognition in highly legible typefaces for general, children, dyslexic, visually impaired and ageing readers,Typography, accessed 2 June 2020.

GOV.UK (2016) A-to-Z: numbers’, Style guide, GOV.UK, accessed 2 June 2020.

References

American Psychological Association (2020) ‘Numbers’, Publication manual of the American Psychological Association, 7th edn, American Psychological Association, Washington DC.

Australian Broadcasting Corporation (2020) ‘Numbers, measurements’, The ABC style guide, ABC website, accessed 3 June 2020.

Btb Translation Bureau (2020) ‘Numerical expressions’, The Canadian style, Btb Translation Bureau website, accessed 3 June 2020.

ChicContent Design London (2019) ‘Grammar points: numbers’, Content Design London readability guidelines, Content Design London website, accessed 3 June 2020.

European Commission (2020) ‘6: Numbers’, English style guide: a handbook for authors and translators in the European Commission, European Commission website, accessed 3 June 2020.

General Services Administration (n.d) ‘Numbers and percentages’, 18F content guide, 18F Content Guide website, accessed 3 June 2020.

Loranger H (23 March 2014) ‘Break grammar rules on websites for clarity’, Nielsen Norman Group, accessed 3 June 2020.

New Zealand Government (2020) ‘Numbers’, Content design guidance, Digital.govt.nz, accessed 3 June 2020.

NSW Government (2020) ‘Numbers, dates and times’, digital.nsw, accessed 17 September 2021.

Oxford University Press (2016) ‘11.2.2: Figures or words?’, New Oxford style manual, Oxford University Press, Oxford.

TechCommNZ (May 2016) ‘Five or 5? Words versus numerals ...’, TelecommNZ Newsletter, accessed 3 June 2020.

Treasury Board of Canada Secretariat (2018) '4.6: Numbers', Canada.ca content style guide, Canada.ca, accessed 3 June 2020.

University of Chicago (2017) 'Numbers', Chicago manual of style, 17th edn, University of Chicago Press, Chicago.

US Government Publishing Office (2016) ‘Numerals’, Government Publishing Office style manual, U.S. Government Publishing Office, accessed 17 September 2021.

This page was updated Wednesday 5 October 2022.