Chicago Citation Format: Rules and Examples
Chicago style comes from The Chicago Manual of Style, whose 18th edition was published in 2024. It offers two systems: notes-bibliography, common in history and the humanities, and author-date, common in the sciences and social sciences.
Updated 21 October 2026 · EssayWriting.com editorial team
- The Chicago Manual of Style is in its 18th edition (2024).
- Notes-bibliography (footnotes) suits humanities; author-date suits sciences and social sciences.
- Chicago now prefers short notes to ibid. for repeated citations.
Many instructors still teach the 17th edition (2017). The core patterns below are shared; check which edition your course requires. Students often use Turabian, a student version of Chicago.
Notes-bibliography vs author-date
| Notes-bibliography | Author-date | |
|---|---|---|
| Common in | History, literature, arts, philosophy | Natural and social sciences |
| In the text | Superscript number linking to a footnote or endnote | (Lopez 2021, 34) |
| Source list | Bibliography | References |
| Repeat citations | Short notes | Same parenthetical form |
How Chicago footnotes work
- Place the superscript number at the end of the clause or sentence, after punctuation (except a dash).
- Number notes consecutively throughout the paper.
- Give a full note the first time you cite a source and a short note afterwards.
- Chicago recommends short notes rather than "ibid." for consecutive citations of the same source; some instructors still accept ibid.
- Include a bibliography unless your instructor says full notes alone are enough.
Worked examples: notes-bibliography
All sources are fictional examples created to show the format.
Book, one author
Full note: 1. Maria Lopez, The Quiet Coast, 2nd ed. (Harbor Press, 2021), 34.
Short note: 2. Lopez, Quiet Coast, 36.
Bibliography: Lopez, Maria. The Quiet Coast. 2nd ed. Harbor Press, 2021.
The 18th edition makes the place of publication optional; many instructors following the 17th edition still expect it, for example (New York: Harbor Press, 2021).
Book, two or three authors
Full note: 3. Priya Shah and Daniel Kim, Sleep and Learning (Northfield University Press, 2022), 88.
Bibliography: Shah, Priya, and Daniel Kim. Sleep and Learning. Northfield University Press, 2022.
Chapter in an edited book
Full note: 4. James Okoro, "Tides and Trade," in Coastal Histories, ed. Anna Berg (Northfield University Press, 2019), 50.
Short note: 5. Okoro, "Tides and Trade," 52.
Bibliography: Okoro, James. "Tides and Trade." In Coastal Histories, edited by Anna Berg. Northfield University Press, 2019.
Journal article
Full note: 6. Priya Shah and Daniel Kim, "Sleep and Memory in First-Year Students," Journal of Student Health 18, no. 2 (2023): 105, https://doi.org/10.1234/jsh.2023.018.
Short note: 7. Shah and Kim, "Sleep and Memory," 107.
Bibliography: Shah, Priya, and Daniel Kim. "Sleep and Memory in First-Year Students." Journal of Student Health 18, no. 2 (2023): 101-18. https://doi.org/10.1234/jsh.2023.018.
Newspaper article
Full note: 8. Tom Reyes, "City Expands Night Bus Routes," Daily Ledger, March 4, 2024, https://www.dailyledger.example/night-buses.
Short note: 9. Reyes, "Night Bus Routes."
Chicago allows news articles to be cited in notes only, without a bibliography entry, unless your instructor wants them listed.
Website
Full note: 10. "Healthy Sleep Habits," Sleep Facts Network, June 10, 2023, https://www.sleepfacts.example/habits.
Bibliography: Sleep Facts Network. "Healthy Sleep Habits." June 10, 2023. https://www.sleepfacts.example/habits.
Online video
Full note: 11. Study Lab, "How to Read a Scientific Paper," YouTube, January 12, 2022, 3:15, https://www.youtube.com/watch?v=xxxx.
Thesis or dissertation
Full note: 12. Sara Ahmed, "Harbour Towns and Migration, 1850-1900" (PhD diss., Northfield University, 2020), 88.
Bibliography: Ahmed, Sara. "Harbour Towns and Migration, 1850-1900." PhD diss., Northfield University, 2020.
Notes vs bibliography: the key differences
| Feature | Note | Bibliography |
|---|---|---|
| Author | First name first | Surname first (first author only) |
| Punctuation | Commas; publication facts in parentheses | Full stops between main elements |
| Pages | Specific page cited | Full range for articles and chapters |
| Indent | First line indented | Hanging indent |
Author-date examples
In-text: (Lopez 2021, 34) · (Shah and Kim 2023, 105) · (Sleep Facts Network 2023)
Reference list: Lopez, Maria. 2021. The Quiet Coast. 2nd ed. Harbor Press.
Shah, Priya, and Daniel Kim. 2023. "Sleep and Memory in First-Year Students." Journal of Student Health 18 (2): 101-18. https://doi.org/10.1234/jsh.2023.018.
Note: no comma between author and year in the parenthetical, and the year follows the author in the reference list.
Chicago paper format
- Margins of at least 1 inch; a readable font such as Times New Roman 12 point.
- Double-spaced text; notes and bibliography entries single-spaced with a blank line between entries.
- A title page for class papers if your instructor asks.
- Page numbers in the header or footer.
- Bibliography on a new page titled "Bibliography", entries alphabetical with hanging indents.
Common Chicago mistakes
- Formatting footnotes like bibliography entries (or the reverse).
- Using full notes every time instead of short notes.
- Putting the superscript before the full stop.
- Mixing notes-bibliography and author-date in one paper.
- Forgetting page numbers in notes.
Chicago checklist
- One system used throughout.
- Every note number matches a note; numbering is consecutive.
- Full note on first citation, short notes after.
- Bibliography includes all sources cited in notes (except where Chicago allows notes only).
- Edition requirements (17th or 18th) checked with your instructor.
Other styles
Quick answers to common questions
Do I need a bibliography if I use full footnotes?
Chicago allows full notes without a bibliography in some cases, but most instructors require one. Check your brief.
Where do footnote numbers go?
After the punctuation at the end of the clause or sentence, except before a dash.
How do I cite the same source twice in a row?
Use a short note. Chicago now recommends short notes over ibid.
Frequently asked questions
What is the latest edition of the Chicago Manual of Style?
The 18th edition, published in 2024. Many courses still use the 17th edition, so check your requirements.
Does Chicago style use footnotes?
The notes-bibliography system uses footnotes or endnotes. The author-date system uses parenthetical citations.
Does Chicago use ibid.?
Chicago recommends short notes instead of ibid., but some instructors still accept ibid.
Is Chicago the same as Turabian?
Turabian is a student-focused adaptation of Chicago. The citation patterns are nearly identical.
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