Fractions and decimals
Be consistent in your use of numbers. When you write about numbers used in examples or UI, duplicate them exactly as they appear in the UI. In all other content, follow the guidelines below.
Numerals vs. words
In body text, spell out whole numbers from zero through nine, and use numerals for 10 or greater. It’s OK to use numerals for zero through nine when you have limited space, such as in tables and UI.
|Use numerals for||Examples|
|Measurements of distance, temperature, volume, size, weight, pixels, points, and so on—even if the number is less than 10.||3 feet, 5 inches|
80 × 80 pixels
|A number the customer is directed to enter.||Enter 5.|
|A round number of 1 million or more.||7 million|
|Dimensions. Spell out by, except for tile sizes, screen resolutions, and paper sizes. For those, use the multiplication sign (×). Use a space before and after the multiplication sign.||10-foot cable|
4 × 4 tile
8.5" × 11" paper
1280 × 1024
|Time of day. Include AM or PM.|
Exception Don’t use numerals for 12:00. Use noon or midnight instead.
Include the time zone if you’re discussing an event, and customers beyond the local time zone may see it. Time stamps in UI and websites usually display local time and date automatically.
The meeting is at noon.
The event starts at 5:00 PM Pacific Time.
The date changes at midnight.
|Percentages, no matter how small. Use a numeral plus percent to specify a percentage. Use percentage when you don’t specify a quantity.||At least 50 percent of your system resources should be available.|
Only 1 percent of the test group was unable to complete the task.
A large percentage of system resources should be available.
|Coordinates of tables or worksheets and numbered sections of documents.||row 3, column 4|
Commas in numbers
Use commas in numbers that have four or more digits, regardless of how the numbers appear in the UI.
Exception When designating years, pixels, or baud, use commas only when the number has five or more digits.
1920 × 1080 pixels
10,240 × 4320 pixels
Don’t use commas in page numbers, addresses, or after the decimal point in decimal fractions.
15601 NE 40th Street
Numbers in dates
Don’t use ordinal numbers, such as June first or October twenty-eighth, for dates. Use a numeral instead: June 1, October 28.
Global tip To avoid confusion, always spell out the name of the month. The positions of the month and day vary by country. For example, 6/12/2017 might be June 12, 2017 or December 6, 2017.
Form a negative number with an en dash, not a hyphen:
Hyphenate compound numbers when they’re spelled out.
the twenty-first day
Fractions and decimals
Express fractions in words, as symbols, or as decimals, whichever is most appropriate. In tables, align decimals on the decimal point. Add a zero before the decimal point for decimal fractions less than one, unless the customer is asked to enter the value.
- 0.5 cm
- enter .75"
Don’t use numerals separated by a slash to express fractions.
½ + ½ = 1
Hyphenate spelled-out fractions. Connect the numerator and denominator with a hyphen unless either already contains a hyphen.
- one-third of the page
- two-thirds completed
In measurements where the unit of measure is spelled out, use the plural form when the quantity is a decimal fraction. Use the singular form only when the quantity is 1.
- 0.5 inches
- 0 inches
- 1 inch
- 5 inches
Ranges of numbers
In most cases, use from and through to describe a range of numbers.
- from 9 through 17
- Use an en dash in a range of pages or where space is an issue, such as in tables and UI. For example, 2016–2020 and pages 112–120.
- Use to in a range of times. For example, 10:00 AM to 2:00 PM.
- Don’t use from before a range indicated by an en dash, such as 10–15.