TitleCasePro logo TitleCasePro
Books · Publishing · History · Arts & Humanities

Chicago Title Capitalization

CMOS 17 capitalises all major words. Short prepositions (≤4 chars) are lowercase, but longer ones like "About" and "Between" are capitalised.

0 words · 0 chars
Your capitalized title will appear here…

Chicago capitalization rules

  • Capitalise all major words
  • Lowercase: articles (a, an, the)
  • Lowercase: coordinating conjunctions (FANBOYS)
  • Lowercase: prepositions ≤4 letters (at, by, for, in, of, on, to)
  • Capitalise: prepositions ≥5 letters (About, Above, Between…)
  • Always capitalise first and last word
  • Capitalise both parts of a hyphenated compound

Read the full Chicago title capitalization rules with examples.

Other style guides

When to Use Chicago Title Capitalization

Chicago title case is the standard for Books, Publishing, History, Arts & Humanities writing. CMOS 17 capitalises all major words. Short prepositions (≤4 chars) are lowercase, but longer ones like "About" and "Between" are capitalised. When your work will be reviewed, published, or cited within these fields, using the correct capitalization style shows attention to detail and compliance with professional standards.

Chicago Title Case vs Other Styles

Title capitalization is not universal. The same title formatted in Chicago style will look different from APA, Chicago, MLA, or AP — and each difference is intentional. Use the style comparison tool to enter your title and see all nine styles side by side. If you need to convert a large list of titles, the batch capitalizer handles CSV and TXT imports for bulk workflows.

Deep-dive: Chicago style title case rules explained.

How the Chicago Capitalizer Works

Paste your title into the tool above. Select Chicago as the active style and the result appears immediately. Click "Explain" to see the rule applied to each word. Use the copy button or press ⌘↵ to copy the output. Everything runs in the browser — no account, no signup, no data sent to a server.

About Chicago Title Case

Chicago title case is defined by the Chicago Manual of Style, 17th edition (2017), and is the standard for book publishing, academic monographs, history writing, and general non-fiction. Chicago uses a preposition-length rule: prepositions of four letters or fewer (at, by, for, in, of, on, to, up, with, from, into, over) stay lowercase, while prepositions of five or more letters (About, Above, Across, After, Among, Between, Beyond, During, Through, Without) are capitalized. This makes Chicago distinctly different from APA and MLA, which lowercase all prepositions. A title like "A Study About the World" capitalizes "About" in Chicago but not in APA.

Chicago Title Case Examples

These examples are generated in real time by the same engine that powers the tool above — every result is guaranteed to match the tool's output.

Original (lowercase) Chicago Style
the quick brown fox jumps over the lazy dog The Quick Brown Fox Jumps over the Lazy Dog
a guide to writing about the world A Guide to Writing About the World
why sleep is important for students Why Sleep Is Important for Students
learning through failure and success Learning Through Failure and Success
notes on the art of writing without fear Notes on the Art of Writing Without Fear
how to capitalize titles in academic writing How to Capitalize Titles in Academic Writing
the effects of social media on mental health The Effects of Social Media on Mental Health
introduction to machine learning with python Introduction to Machine Learning with Python

Common Chicago Edge Cases

  • "With" has exactly 4 letters — it stays lowercase in Chicago even though it looks substantial.
  • "Into" (4 letters) stays lowercase. "Until" (5 letters) gets capitalized.
  • Coordinating conjunctions "so" and "yet" — Chicago capitalizes these when they function as adverbs, not conjunctions.
  • First and last word are always capitalized, even if they are short prepositions like "of" or "in."
  • The first word after a colon is always capitalized. The second part of a subtitle starts with a capital.

Chicago vs Bluebook

Chicago and Bluebook produce nearly identical title case because Bluebook's rules closely follow Chicago's preposition-length threshold. Both capitalize prepositions of five or more letters and lowercase shorter ones. The main practical differences appear in citation formatting rather than in title case itself. Bluebook adds legal-specific rules for case names, statutes, and abbreviations, while Chicago is the broader publishing standard. For general title capitalization of headings and article titles, the two styles are interchangeable.

Chicago capitalization FAQ

Common questions about using TitleCasePro for Chicago title case.

Related Tools