Using Abbreviations in Chicago Format – A Clear Guide


Abbreviations are essentially the shortened version of a phrase or word. The way abbreviations are to be used in a paper or essay is entirely dependent on the writing format you are using. Each writing format has its specific rules for abbreviations. The Chicago style is no exception to this, it, however, distinguishes between acronyms, contractions and initialism, but they are all grouped under abbreviation. (Also learn about using abbreviations in APA and MLA format)

Acronyms refer to the shortened version of words or phrases that are based on the initial letter of the various elements or words and are readable as a single word. In contrast, initialism, unlike acronyms, is readable as a series of letters. Contraction, however, refers to the abbreviations of words that usually include the first and last letter of the word. Here we have listed a number of rules for using abbreviations in Chicago format.

Guidelines for Using Abbreviations in Chicago Format

  • Always introduce your abbreviation: The first time you are using an abbreviation or an acronym, you are expected to spell it out and put the abbreviation in parenthesis. (Find out where to use parentheses)
  • When in doubt, always spell out in full: In an event you do not know if the abbreviation is widely accepted or if it conforms to the style, it is better you just spell it out.
  • Use, i.e. only when you intend to rephrase the statement you made earlier.
  • Use, e.g. only when you want to offer an example and do not end it with etc.
  • Both, i.e., and, e.g. should be followed by a comma.
  • Only capitalize abbreviations if the words they stand for would have been capitalized if written in full otherwise, write them in lower case.
  • Use period with abbreviations that end with lower case letters. For example, a.k.a., a.m., p.m.
  • Do not indicate the abbreviation or acronym of a word or phrase if it is not used anywhere else in the document.
  • The word “the” in a company name is usually omitted in the acronym.
  • Do not use abbreviation nor acronym in a direct quote.

Abbreviate the Following

check-mark The title before names

All the title that comes before a person’s name should be abbreviated

For example

Mr., Ms., Prof.

check-mark The title after names

All titles that come after a person’s name should be abbreviated

For example

M.D., B.A., M.A.

check-mark Name of familiar institutions

The names of institutions that people are familiar with should always be abbreviated

For example


check-mark Names of countries and corporation

The names of countries that their abbreviation are widely known should be abbreviated. Corporations that go by their abbreviations more than their full names should also be abbreviated.

For example



check-mark Names of famous people and familiar object

The names of famous people are allowed to be abbreviated. The same goes for very familiar objects that we are used to their abbreviations

For example



check-mark Mathematical units or words that are used with numbers

All mathematical units are allowed to be abbreviated as well as words that are used after a number.

For example

17 in., 25 ft, 150 kg

7:00 a.m., 520 B.C., 103 A.D.

Note a.m. and p.m. can either be written in uppercase or lowercase.

check-mark Common Latin words

Latin terms that are commonly used are allowed to be abbreviated.

For example

etc., i.e., e.g., et al.

check-mark Names of states and territories

When making reference to them or using them in an address, states and territories are allowed to be abbreviated. Do not use a period after state abbreviations. State abbreviations must be in line with the accepted abbreviations by the U.S. Postal Service.

For example


Do Not Abbreviate the Following:

  • Words that begin a sentence
  • The name of the months in the year, as well as the names of the days of the week
  • The name of an individual.
  • Names of courses.


Scientific editor

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