Numbers, Dates and Locations

 

General

  • Spell out numbers one through nine; use numerals for 10+
  • Ages are always numerals: 3-year-old boy, 10-year-old building
  • Use numerals for measurements: 1 inch, 7 miles per hour, 20 seconds
  • Use ½ for half-day activities: 1 ½
  • Dimensions are expressed without hyphen: 2D, 3D, 4D
  • Use numeral-word combination for millions, billions, trillions: $62 million, 62 billion people
  • Phone number format: 1-630-571-2670 x123
  • When listing a range of dates or values, do not use spaces between the dash and the numerals.

Percent

  • Use the % sign when paired with a numeral, with no space: Average hourly pay rose 3.1% from a year ago; her mortgage rate is 4.75%; about 60% of Americans agreed; he won 56.2% of the vote. Use figures:  4 percentage points.
  • For amounts less than 1%, precede the decimal with a zero: The cost of living rose 0.6%.
  • In casual uses, use words: She said he has a zero percent chance of winning.
  • Constructions with the % sign take a singular verb when standing alone or when a singular word follows an of construction: The teacher said 60% was a failing grade.
  • It takes a plural verb when a plural word follows an of construction: He said 50% of the members were there.
  • Use decimals, not fractions, in percentages: Her mortgage rate is 4.5%.
  • For a range, 12% to 15%, 12%–15% and between 12% and 15% are all acceptable.
  • Use percentage, rather than percent, when not paired with a number: The percentage of people agreeing is small.
  • When saying an amount is more than a certain percent, use +%: 75+% come to see new products and developments.

Times

  • Use a.m. and p.m.
  • Use hours:minutes (4:30) unless on the hour, then 4 p.m.
  • Use noon or midnight in place of 12 for clarity
  • Ranges: 9–11 a.m. or 9 to 11 a.m., 9 a.m.–3 p.m. or 9 a.m. to 3 p.m.
  • Abbreviate time zones on first reference: CT; ET; PT, etc.

Dates

  • When a month is used with a specific date, abbreviate only Jan., Feb., Aug., Sept., Oct., Nov. and Dec. Spell out when using alone, or with a year alone. 
  • Use commas for full dates (Sept. 20, 2020), no comma for month and year (September 2020).
  • Do not use ordinals with dates: Sept. 3 versus Sept. 3rd Sept. 3rd.
  • For a date or time range, use en dash, Nov. 1–12 or 1:30–2:30 p.m. 
     

Locations

  • Use periods in the abbreviation for the United States, U.S.  In headlines, however, the abbreviation has no periods.
  • When listing state abbreviations, use the two-letter postal abbreviation: IL, IN, MI, MO, etc. Do not use the longer AP style abbreviation.

Em dash (—) and En dash (–)

  • Em dashes (—) are used to signal abrupt change; as one option to set off a series within a phrase; before attribution to an author or composer in some formats; after datelines; and to start lists.
  • Do not use spaces on either side of the em dash. For example: Please call my radiologist—Richard Smith, MD—on Tuesday.  
  • For a date or time range, use en dash. For example, Nov. 1–12 or 1:30–2:30 p.m.