Numbers

The Readability Guidelines include detailed guidelines on the following topics:

• Use numerals instead of words for numbers.
• Choose clear typography.
• Be specific with data.
• Use a percent sign for percentages.
• Use ‘to’ for number ranges, not a hyphen or any other type of dash.
• Use a space before KB and MB.

Numbers in the Readability Guidelines

Cardinals and ordinals — 1, 2, 3 and first, second, third

Cardinal numbers say how many of something there are, such as 1, 2, 3.

Ordinal numbers tell you the position of something, such as first, second, third.

How to write cardinals and ordinals:

• Use numerals for cardinal numbers from 0 to 999,999.
• Use words for ordinal numbers from first to ninth.

Big numbers

• Use commas to separate thousands when the number is over 1,000.
• For numbers in the millions, use the word ‘million’ instead of writing out the number in full. However, for some content write the number in full, for example technical data.

Headings are an exception

If a heading starts with a number, write it as a word, unless it’s a year.

Dates and times

• Write dates as day, month, year in full.
• Do not use ordinal numbers, for example, 1st or 3rd, in dates.
• Show time using a 12-hour clock.
• Show start and end times in full.
• Use ‘midnight’ not ‘00:00’.
• Spell out the names of days and months in full.

Use ‘to’ instead of an en dash (–) in date and time ranges as it’s easier for screen readers to read out.

Currency

Put the currency code and currency symbol before any monetary amounts.

Phone and fax numbers

Always use freephone (rather than phone) for a freephone number (such as 0800, 0508).

If it’s a New Zealand freephone, always put ‘(NZ only)’ after the number.

Use freefax rather than free fax.

Use cellphone, rather than cell-phone or cell phone.

Use TTY: as the label for any number that provides a text service for the deaf community.

Unless they’re used in the middle of a sentence, phone, freephone, email and website should always have a colon after them.

Do not use bullet points for contact details — they are not a ‘list’ so shouldn’t be marked up as one.

Code for phone numbers

To make your phone numbers clickable:

<a href="tel:0044555555">+44 555 555</a>

Write phone numbers with non-breaking spaces between the groups of numbers. A non-breaking space keeps the whole number on 1 line — in HTML it’s coded as ‘&nbsp;’. Numbers are grouped based on your organisation’s style.

Include the plus sign and the international country code with phone numbers.