Use words from one to nine and then numerals from 10 upwards. Always use words at the start of a sentence. Where using a numeral adds impact, exceptions are OK but use these sparingly.
Numbers with more than three digits take commas:
Use million or billion for numbers above 999,999.
Spell out days of the week and months.
Saturday 24 January
Decimals and fractions
Spell out fractions.
Use a decimal when a number can’t be easily written out as a fraction, like 1.375 or 47.2.
Use the % symbol instead of spelling out "per cent".
Ranges and spans
Use a hyphen (-) to indicate a range or span of numbers.
It takes 20-30 days.
When writing about currency, use the symbol before the amount.
Include a decimal and number of cents if more than 0.
Use a space to separate the area code from the rest of the number. Our users are all over the world, and so are we, so always use a country code.
+44 20 78658100
Use the degree symbol and the capital C abbreviation for Celsius.
Use numerals and am or pm, with no space in between. Use dots not colons between hours and minutes. Don’t use minutes for on-the-hour time.
Use midnight and noon or midday, not 12am, or 12pm, which can be confusing.
Use a hyphen between times to indicate a time period.
When referring to international time zones, spell them out: Nepal Standard Time, Australian Eastern Time. If a time zone does not have a set name, use its Coordinated Universal Time (UTC) offset.
Abbreviate decades when referring to those within the past 100 years:
When referring to decades more than 100 years ago, be more specific: