Chicago and Turabian style, explained

Chicago is the style with two systems inside it, which is why it feels harder than it is. Work out which one you have been asked for and most of the confusion goes.

Updated 20 September 2026 · 8 min read

Chicago style comes from The Chicago Manual of Style, currently in its 18th edition. Turabian — A Manual for Writers — is the student version of the same rules, so if you have been told “Turabian”, everything here applies.

First, work out which system you need

Chicago contains two citation systems, and they look nothing alike.

System	Looks like	Used in
Notes and bibliography	Superscript numbers, footnotes, a bibliography	History, literature, art, theology — the humanities
Author–date	`(Okafor 2024, 17)` and a reference list	Sciences and social sciences

If nobody told you which, the subject is the best guide — and notes and bibliography is what most people mean when they say “Chicago”. Ask if you can; guessing wrong means reformatting every citation.

Page setup

Margins of at least 1 inch
A readable 12 pt serif — Times New Roman is the usual choice
Double-spaced body text. Footnotes and bibliography entries are single-spaced internally, with a blank line between entries
Page numbers top right, starting on the first page of text
Paragraph first lines indented 0.5 inch

Notes and bibliography

A superscript number goes at the end of the sentence, after the punctuation. The note itself sits at the foot of the page.

In the text

The collapse was structural rather than psychological.¹

The first note for a source gives it in full. Later notes for the same source are shortened — author surname, short title, page.

First note

1. Helen Marsh, Credit and Collapse (Chicago: Riverbank Press, 2021), 142.

Shortened note

2. Marsh, Credit and Collapse, 155.

The 17th edition deprecated ibid. in favour of the shortened form, and the 18th keeps that. Use the shortened note even for an immediately repeated source.

The bibliography

Alphabetical by surname, hanging indent, on its own page headed Bibliography. The entries differ from the notes in three ways that are easy to miss:

The author's name is inverted — Marsh, Helen.
Elements are separated by full stops rather than commas
Publication details are not in brackets

Note versus bibliography

Note: 1. Helen Marsh, Credit and Collapse (Chicago: Riverbank Press, 2021), 142.

Bibliography: Marsh, Helen. Credit and Collapse. Chicago: Riverbank Press, 2021.

Journal article, bibliography

Okafor, Amara. “Margin Lending before 1929.” Journal of Economic History 18, no. 2 (2024): 114–29. https://doi.org/10.1000/jeh.2024.114.

Chapter in an edited book, bibliography

Ibrahim, Sara. “Banks and Brokers.” In The Long Twenties, edited by Kwame Doyle, 201–24. Manchester: Northgate Academic, 2022.

Author–date

The other system. Citations are parenthetical, and the list at the end is headed References.

In the text

The collapse was structural rather than psychological (Marsh 2021, 142).

Reference list entry

Marsh, Helen. 2021. Credit and Collapse. Chicago: Riverbank Press.

Note there is no comma between author and year, but there is one before the page number. The year moves to just after the author's name in the list.

Details worth getting right

Titles are in headline style — major words capitalised.
Book and journal titles in italics; article and chapter titles in quotation marks.
Page numbers in notes appear without p. or pp.
Chicago abbreviates number ranges: 114–29, not 114–129.
A bibliography lists works you consulted; notes cite what you used at that point. They are related but not identical.

A checklist before you submit

You are using the system you were asked for, consistently
Note numbers run in order and sit after the punctuation
The first note for each source is full; later ones are shortened
No ibid.
Bibliography inverted, alphabetical, full stops between elements, hanging indent
Headline-style capitalisation throughout