How to Write a Book Index in 2026: Step-by-Step Guide 📑

You write a book index by reading your final, page-numbered proofs and pulling out every concept, name, and term a reader would look up — then organizing those terms alphabetically with page numbers, subentries, and cross-references. It takes most authors 20 to 40 hours for a 250-page nonfiction book.

In this guide, you’ll learn:

How to tell whether your book actually needs an index
The exact step-by-step process, from proof-reading to final alphabetization
How to structure entries, subentries, locators, and cross-references the way Chicago does it
The real Word and InDesign workflows, plus what a professional indexer costs in 2026

Here’s the process, starting with the decision most authors get wrong.

Does Your Book Need an Index?

Your book needs an index if a reader would ever want to find one specific thing in it without reading it front to back. That means nearly all nonfiction: how-to books, business books, biographies, textbooks, cookbooks, technical manuals, and academic monographs. Fiction, memoir, and poetry almost never need one.

The test isn’t genre — it’s use pattern. A reference book gets read in fragments. A narrative gets read in order.

Ask yourself: will anyone ever pick this book up months later and think, “where was that part about pricing?” If yes, you need an index.

Books that need an index:

Business, marketing, and self-help books with named frameworks
Textbooks, technical manuals, and academic works (traditional publishers usually require one)
Cookbooks (indexed by ingredient and dish name)
History and biography with many people, places, and dates
Any book you want to be cited from

Books that don’t:

Novels, short story collections, poetry
Straight narrative memoir with no reference value
Short ebooks under about 100 pages
Books that are essentially long essays

One practical warning for self-publishers: an index is tied to fixed page numbers, so it works in print but breaks in reflowable ebooks. Most ebook indexes use hyperlinked entries instead of page numbers, or get dropped entirely. Plan a print index and a linked ebook version separately.

If you’re still mapping out what belongs at the end of your book, our guide to the back matter of a book covers the full running order — index, glossary, appendix, bibliography, and more.

What Is a Book Index?

A book index — an alphabetical list of the concepts, names, and terms in a book, each followed by the page numbers where that topic is discussed. It sits in the back matter, after the appendices and bibliography, and it is almost always the last element in the book.

An index is not a word list. A search-and-replace tool can find every occurrence of “leadership”; only a human can decide which four of those 37 mentions are actually about leadership.

That distinction is the whole craft. A good index records discussions, not appearances.

People often confuse this with a glossary, which is a different animal entirely — see our breakdown of the difference between an index and a glossary if you’re deciding whether you need one, the other, or both.

How to Write a Book Index: The 8-Step Process

You write a book index in eight steps: finalize your page proofs, read for indexable concepts, mark terms, build raw entries, group them into subentries, add cross-references, alphabetize and edit, then format and proofread. Each step below covers what to actually do.

Step 1: Wait for Final Page Proofs

Do not start indexing until your interior layout is locked and page numbers will not move again. This is non-negotiable.

If a single paragraph gets added in chapter 3, every page number after it shifts, and your entire index becomes wrong. Professional indexers only work from final, paginated PDFs for exactly this reason.

In a traditional publishing timeline, indexing happens in the two to four week window between final proofs and printing. In self-publishing, do it after your formatting is done and before you upload.

That means trim size, fonts, margins, images, and front matter all have to be settled first. If you’re still choosing tools for the interior, our roundup of book formatting software covers the layout stage that has to close before indexing opens.

Step 2: Read the Whole Book Again

Read your book straight through, cover to cover, as a reader would. Not skimming — reading.

You’re looking for two things: what the book actually discusses, and what vocabulary a reader would use to look those things up. Those are frequently different words.

If your book calls it “asymmetric client acquisition” but every reader thinks of it as “cold outreach,” you need entries under both, with a cross-reference connecting them. This is the single biggest gap between an amateur index and a professional one.

Step 3: Mark Every Indexable Term

Go through again — this time marking. Highlight or tag every term that meets the “substantive discussion” bar.

Index these:

Concepts, methods, and frameworks the book explains
People, organizations, and place names
Technical terms and jargon you define
Titles of works you discuss (books, films, studies)
Events, dates, and case studies
Anything you gave a heading or subheading to

Don’t index these:

Passing mentions with no substance (“as Napoleon once said”)
Words in your table of contents that aren’t discussed elsewhere
Terms from your front matter, dedication, or acknowledgments
Every occurrence of a word that appears on every page
Your own name, unless the book discusses you as a subject

The rule professional indexers use: if a reader turned to that page expecting information on the term and found only a name-drop, don’t index it.

Step 4: Build Your Raw Entry List

Now create your working list. Every marked term becomes an entry with its page number attached — this is your raw material, and it will be messy.

Use a spreadsheet, dedicated indexing software, or Word’s index fields. The format matters less than capturing everything before you start organizing.

At this stage, record entries exactly as they appear. Don’t merge, don’t sort, don’t edit. You’ll have hundreds of rows. That’s correct.

For a 250-page book, expect roughly 500 to 750 raw entries before editing. The Chicago Manual of Style offers a useful benchmark here: the total number of entries, including subentries, should run to about twice the number of text pages, and the finished index typically occupies around 5 percent of the book’s page count.

Step 5: Structure Entries and Subentries

Once you have your raw list, group related entries under a main heading with subentries beneath. Any main entry with more than about five or six page numbers needs breaking up.

A string of undifferentiated locators is useless to a reader:

pricing, 34, 47, 52, 89, 91, 103, 118, 140, 156

That tells your reader nothing. Compare it with the subentry version:

pricing
  anchoring effects, 89-91
  cost-plus method, 34
  discount strategy, 140, 156
  psychological thresholds, 103
  value-based method, 47-52
  See also positioning; profit margin

The second one is a navigation tool. The first is a lottery ticket.

Rules for subentries:

Break up any entry with more than five or six locators
Subentries are alphabetized by their first significant word, ignoring prepositions (“in,” “of,” “and”)
Keep subentries short — a few words, not a sentence
Two levels is plenty. Sub-subentries belong in academic and technical works only
Don’t create a subentry with only one page reference unless the main entry is genuinely crowded

Chicago recognizes two layouts. Run-in style puts subentries in a single paragraph after a colon, separated by semicolons — it saves space and is common in trade books. Indented (stacked) style puts each subentry on its own line, as in the example above, and is far easier to scan. Indented style is standard for reference and technical books, and it’s what most self-published nonfiction should use.

Step 6: Choose the Right Main Heading Wording

Main headings should be nouns or noun phrases, not verbs or full sentences. “Delegation” not “how to delegate.” “Team meetings” not “running effective team meetings.”

Invert names and titles so the alphabetizable word comes first. People go surname-first: Drucker, Peter. Titles beginning with an article get inverted too: A Tale of Two Cities becomes Tale of Two Cities, A, filed under T.

Start every main heading with a lowercase letter unless the term is a proper noun. marketing funnels and Maslow, Abraham both appear under M, one lowercase and one capitalized. This is standard Chicago practice and it looks wrong until you’ve seen a few real indexes.

Step 7: Add Locators and Cross-References

A locator is the page number (or number range) that follows an index entry. Get the ranges right, because ranges are where most amateur indexes fall apart.

Locator rules:

Situation	Format	Example
Single page	Plain number	`budgeting, 47`
Continuous discussion	Full range with en dash	`budgeting, 47–52`
Separate discussions	Comma-separated	`budgeting, 47, 89, 134`
Scattered across a range	Use `passim` sparingly	`budgeting, 47–63 passim`
Main discussion emphasized	Bold or italic the key locator	`budgeting, 47, 89–94, 134`
Footnote reference	Page plus note number	`budgeting, 210n4`
Figure or table	Page plus label	`budgeting, 52 (fig. 3.1)`

A cross-reference points readers from one term to another. There are two kinds, and they do different jobs.

See sends the reader somewhere else entirely, because the term they looked up has no entries of its own:

cold outreach. See client acquisition

See also points to additional related material after the reader has already found real entries:

client acquisition, 22-31
  cold email, 24
  referrals, 28-31
  See also networking; sales funnels

Both see and see also are set in italics, preceded by a period, and placed after the entry’s own locators. Always verify that every cross-reference target actually exists as an entry — broken cross-references are the most common defect in self-made indexes.

A practical alternative to a see reference is double-posting: listing the same page numbers under both terms. If “cold outreach” only has two locators, just repeat them under both headings rather than sending the reader on a second lookup. Use see references when the target entry is large.

Step 8: Alphabetize, Edit, and Proofread

Alphabetize your entries, then edit ruthlessly, then proofread against the actual pages.

There are two alphabetization systems and you must pick one and stay consistent. Letter-by-letter ignores spaces and treats each entry as one continuous string. Word-by-word treats a space as coming before any letter. They produce different orders:

Letter-by-letter	Word-by-word
newborn	new business
new business	new media
newsletter	newborn
new media	newsletter

Chicago prefers word-by-word for most books; letter-by-letter is common in scientific and technical works. Either is correct. Mixing them is not.

Then edit. Merge near-duplicate headings, delete single-locator entries that add nothing, break up any entry that grew past six locators, and cut terms that appear on nearly every page.

Finally, proofread by spot-checking. Pull 30 to 50 entries at random and physically turn to those pages to confirm the content is there. Every wrong page number costs you reader trust.

If you’re still tightening up the rest of your manuscript, our guide to proofreading vs editing covers which passes to run before you ever reach page proofs.

How to Create an Index in Microsoft Word

You create an index in Microsoft Word by marking entries with the References tab, then inserting a generated index that Word builds from those marks. It’s free, it’s built in, and it handles page numbers automatically when text shifts.

The Word workflow:

Finish your layout and page numbering.
Select the word or phrase you want to index.
Go to References → Mark Entry (or press Alt+Shift+X).
In the dialog, edit the Main entry text and add a Subentry if needed.
For a page range, first bookmark the range, then choose Page range → Bookmark.
For a cross-reference, select Cross-reference and type the target term.
Click Mark, or Mark All to tag every instance of that exact word in the document.
Repeat for every entry, then place your cursor at the end of the book.
Go to References → Insert Index, pick indented or run-in format, set columns, and click OK.
After any edit, click inside the index and press F9 to update page numbers.

Word inserts a hidden XE field code next to each marked term. Toggle these on and off with Ctrl+Shift+8 — they change your line breaks while visible, so hide them before checking your final pagination.

If you drafted in Google Docs, export to Word before you start — Docs has no native indexing tool and no equivalent to XE field codes.

Word’s limitations: Mark All is a trap, because it indexes every literal instance including passing mentions. There’s no easy way to see your whole entry list at once, editing a term means hunting down each field code, and Word can’t do sophisticated sorting. It’s workable for a 150-page book. It’s painful for a 400-page one.

How to Create an Index in Adobe InDesign

You create an index in InDesign using the Index panel (Window → Type & Tables → Index), which stores entries as topics separate from the page references — a more robust model than Word’s inline field codes.

The InDesign workflow:

Open the Index panel and switch to Reference mode.
Select text on the page, then click New Page Reference (or Ctrl/Cmd+7).
Set the entry text and up to four subentry levels in the dialog.
Choose the reference type: Current Page, To End of Section, To Next Style Change, or a range.
Use See or See also from the same type dropdown for cross-references.
Click Add or Add All and repeat.
When finished, click Generate Index, set your formatting options, and place the resulting story.

InDesign’s edge is that entries are anchored to text, not page positions — reflow the book and the index follows. You can also edit the master topic list in one panel instead of hunting through the document, and index across multiple documents in a book file.

InDesign’s limitations: the generated index is a static text story, so any change means regenerating and re-styling. Sorting options are limited compared to dedicated software, and the panel workflow is slow for high entry counts.

How to Create an Index for a Book Without Software

You can build a complete index with nothing but a spreadsheet and your final PDF. It’s slower than marker tools, but it gives you total control over wording, and it’s the most reliable option for a short book you don’t want to re-lay-out in Word.

The two-column method:

Open a spreadsheet with two columns: term and page.
Read your final, paginated proofs straight through, typing each indexable term and its page number as a new row. Don’t merge or tidy anything yet.
When you’re done, sort by term. Identical terms now sit together.
Merge duplicates onto one line, collapsing consecutive pages into ranges (47, 48, 49 becomes 47–52 if the discussion is continuous).
Split crowded terms into subentries in a third column, then sort by term and subentry.
Add your see and see also cross-references as their own rows so they alphabetize into place.
Export or retype the finished list into your layout as two columns.

The catch is maintenance. There are no field codes tying your entries to the text, so if you change a single page after indexing, every locator has to be rechecked by hand. Only use this method on a layout you are genuinely finished with.

It’s also the fastest way to audit an index someone else built: dump the entries into a spreadsheet, sort, and the duplicate headings and inconsistent spellings surface immediately.

Manual vs Software vs Professional Indexer: Which Should You Choose?

Choose based on your book’s complexity and what your time is worth. Here’s the honest comparison.

Approach	Cost	Time (250-page book)	Quality	Best for
Manual in Word	Free	25–40 hours	Fair to good	First books, simple trade nonfiction
InDesign panel	Included with CC	20–35 hours	Good	Authors already formatting in InDesign
Dedicated indexing software	Free–$500	15–30 hours	Very good	Repeat authors, dense reference books
AI-assisted first pass	Varies	8–15 hours	Good with editing	Authors who’ll review every entry
Professional indexer	$600–$1,500	Your time: ~2 hours	Excellent	Academic, technical, and traditionally published books

Dedicated Indexing Software Is Now Mostly Free

Here’s something almost no indexing guide mentions: the three professional indexing programs are now largely free.

Cindex was released as free and open-source software in April 2024, with the full edition available in both the Mac App Store and the Microsoft Store — no demo limits, no student version, no license fee. MACREX, the long-running Windows program, has been free of charge since December 2022. SKY Index Professional 8.0 remains a paid Windows product from SKY Software.

These programs handle what Word can’t: live sorting between letter-by-letter and word-by-word, automatic cross-reference validation, page range compression, duplicate detection, and instant reformatting between run-in and indented styles. If you’re indexing anything longer than 200 pages, download Cindex before you start marking entries in Word.

Where AI Fits

AI is genuinely useful for the first pass and genuinely bad as the last word. It can scan a manuscript and propose candidate terms faster than you can highlight them, which collapses the most tedious part of steps 3 and 4.

What it can’t reliably do is judge substance. AI will confidently index a passing mention of Napoleon in chapter 2 alongside the four pages that actually discuss him.

Treat AI output as a candidate list, not an index. Every entry still needs a human decision about whether the discussion on that page justifies the lookup.

Our Pick — Chapter

Chapter is an AI book writing platform for nonfiction authors. It won’t generate your index for you — it’s a drafting and structuring tool, not indexing software — but it does the thing that makes indexing dramatically easier: it builds your book around a clear, consistent concept hierarchy from the outline stage forward.

Best for: nonfiction authors who want a well-structured manuscript before they reach the indexing stage Pricing: $97 one-time (nonfiction) Why we built it: 2,147+ authors have written books with Chapter, and the ones with clean, consistently named frameworks index in a fraction of the time — because the index is really just the concept map you already built, sorted alphabetically.

Books drafted with disciplined terminology take less time to index than books where the same idea is called three different things across four chapters. That’s a drafting problem, not an indexing problem.

How Much Does It Cost to Hire a Professional Indexer?

Hiring a professional indexer costs $2.50 to $10.00 per page or $22 to $80 per hour, depending on the book’s complexity and the indexer’s experience. For a typical 250-page trade nonfiction book, expect $600 to $1,200.

Rate guidance from the professional bodies as of 2026:

Organization	Hourly rate	Per-page rate
American Society for Indexing (US)	$22.20–$35.52	$2.50–$4.00
Editorial Freelancers Association (US)	$55–$60	$5.00–$6.25
Society of Indexers (UK)	£34.00	£3.80
Indexing Society of Canada	C$20–C$65	C$1.85–C$10.00
ANZSI (Australia / NZ)	A$70 / NZ$55	Quoted per project
AFEPI Ireland	€36.10	€4.00

What pushes you to the high end:

Dense academic or scientific text with heavy terminology
Books with hundreds of proper names (history, biography)
A required depth of indexing (five or six entries per page rather than two)
Rush turnaround inside a week
Multiple indexes (subject index plus name index)

What keeps you at the low end:

Straightforward trade nonfiction with a clear structure
Generous timelines
Books under 200 pages
Clean, final PDFs delivered on schedule

Most indexers quote per project after seeing a sample chapter and your page count. Ask for a sample index of ten pages before committing — it’s the fastest way to check whether their judgment matches your book.

You can find indexers through the American Society for Indexing’s directory, the Society of Indexers, or general freelance marketplaces — though the professional societies vet for actual indexing training in a way that marketplaces don’t. If you’re budgeting for the full production stack, our breakdown of what a book editor costs puts indexing in context against the other freelance line items.

Chicago Manual of Style Index Conventions

The Chicago Manual of Style is the default authority for book indexes in North American publishing. Chapter 16 in the 17th edition (chapter 15 in the 18th) is the full reference. Here are the conventions that matter most.

Length and density. Total entries including subentries should be roughly twice the number of text pages. The finished index should occupy about 5 percent of the book’s total pages. For a general index, five or six locators per text page is about right.

Capitalization. Main headings and subentries start lowercase unless the term is a proper noun.

Punctuation. In run-in style, a colon separates a main heading from its first subentry, and semicolons separate subentries. In indented style, no colon and no semicolons — line breaks do the work. Locators are preceded by a comma.

Cross-references. See and see also are italicized and preceded by a period. Generic cross-references — pointing to a type of heading rather than a specific one — are italicized in full.

Alphabetizing. The first word of a main heading determines placement, which is why titles get inverted. Word-by-word is Chicago’s default preference; letter-by-letter is acceptable if applied consistently.

Placement. The index is the final element of the book. If you have both a name index and a subject index, the name index comes first.

Typography. Indexes are set in two columns at a smaller type size than body text, typically 8 or 9 point, with a ragged right margin.

If your publisher has a house style sheet, it beats Chicago every time. Ask before you start.

Index vs. Glossary vs. Table of Contents

These three navigation elements get confused constantly, and books often need more than one. Each answers a different reader question.

Element	Location	Answers	Order
Table of contents	Front matter	How is this book structured?	Sequential
Glossary	Back matter	What does this term mean?	Alphabetical
Index	Back matter	Where is this topic discussed?	Alphabetical

A table of contents shows your book in reading order — our guide to creating a table of contents covers building one that also works as ebook navigation. A glossary defines vocabulary; see the difference between an index and a glossary if you’re deciding whether you need one, the other, or both.

Reference-heavy books frequently carry all three, and there’s no redundancy in that: a reader who doesn’t know a term reaches for the glossary, and a reader who knows it but can’t find it reaches for the index. For the full running order at each end of the book, see our guides to the front matter of a book and the back matter of a book.

Common Mistakes to Avoid

Indexing before final pagination. Every page number moves and you start over. This is the most expensive mistake on the list.
Using Mark All in Word indiscriminately. It captures every literal instance including trivial mentions, and it produces bloated entries with a dozen useless locators.
Leaving long undifferentiated locator strings. Any entry with more than five or six page numbers needs subentries. Readers won’t check nine pages to find one paragraph.
Broken cross-references. A see reference pointing to an entry you later renamed or deleted is worse than no cross-reference at all. Validate every one.
Indexing only your own vocabulary. If readers call it something else, they’ll never find it. Index both terms.
Mixing alphabetization systems. Pick word-by-word or letter-by-letter and apply it to every entry.
Indexing the front matter. Skip the dedication, acknowledgments, and table of contents.
Skipping the proofread. Wrong page numbers destroy trust in the whole index. Spot-check at least 30 entries against the actual pages.

How Long Does It Take to Write a Book Index?

Writing a book index takes 20 to 40 hours for a 250-page nonfiction book if you do it yourself, or roughly 2 to 4 hours of your time if you hire a professional indexer to do it. Professional indexers work faster — typically 8 to 15 pages per hour — because they use dedicated software and have internalized the judgment calls.

Complexity changes the math considerably. A straightforward business book might take 15 hours. A history with 400 proper names could take 60.

Budget more time than you think for step 5 — grouping raw entries into subentries — because that’s where the actual thinking happens. Marking terms is mechanical. Structuring them isn’t.

Can AI Write a Book Index for You?

AI can produce a solid first-pass candidate list for a book index, but it cannot produce a finished index without human editing. AI reliably extracts terms and page locations; it unreliably judges whether a mention constitutes a substantive discussion worth indexing.

The failure mode is consistent: AI over-indexes. It treats every occurrence as equally significant, which produces exactly the bloated, undifferentiated entries that make an index useless.

Use it to compress steps 3 and 4, then do steps 5 through 8 yourself. That’s roughly a 40 percent time saving with no quality loss — as long as you actually review every entry. For a broader look at where the technology helps and where it doesn’t, see our guide to the best AI tools for nonfiction books.

Do Ebooks Need an Index?

Ebooks generally do not need a traditional page-number index, because reflowable text has no fixed pages. Most ebooks rely on the reader’s built-in full-text search plus a detailed, linked table of contents instead.

If you want indexing functionality in an ebook, build a hyperlinked index — entries that link to anchors in the text rather than to page numbers. EPUB 3 supports this, and both Word and InDesign can generate linked indexes on export.

A practical compromise many self-publishers use: full page-number index in the print edition, hyperlinked chapter-and-section index in the ebook. Amazon KDP handles both formats without issue.

FAQ

Where does the index go in a book?

The index goes at the very end of the book, as the final element of the back matter — after the appendices, notes, bibliography, and glossary. If a book has both a name index and a subject index, the name index comes first. Nothing follows the index except blank pages or publisher advertisements.

What is the difference between an index and a table of contents?

The difference between an index and a table of contents is order and granularity. A table of contents lists chapters in the order they appear, at the front of the book. An index lists specific topics alphabetically, at the back, and points to every page where each topic is discussed regardless of chapter.

How many entries should a book index have?

A book index should have roughly twice as many entries as the book has text pages, counting subentries. A 250-page book typically has 400 to 600 total entries. The Chicago Manual of Style also suggests the finished index should occupy about 5 percent of the book’s total page count.

Can you write an index in Microsoft Word?

Yes, you can write an index in Microsoft Word using References → Mark Entry (Alt+Shift+X) to tag terms, then References → Insert Index to generate the formatted list. Word tracks page numbers automatically and updates them with F9. It works well for books under about 250 pages.

What is the difference between “see” and “see also” in an index?

In an index, see redirects a reader to a different entry because the term they looked up has no page numbers of its own. See also appears after an entry’s own locators and points to additional related entries. Both are italicized and preceded by a period.

Do self-published books need an index?

Self-published nonfiction books need an index if readers will use them as a reference — business books, how-to guides, cookbooks, and technical manuals all benefit. Self-published fiction, poetry, and narrative memoir do not. An index also signals professional production quality to reviewers and librarians.

The Bottom Line

An index is the last thing you build and the first thing a serious reader uses. It’s not a formality — it’s the difference between a book someone reads once and a book someone keeps on the desk.

Work from final proofs. Index discussions, not words. Break up anything with more than six locators. Validate every cross-reference. Proofread against real pages.

And if your book is dense, academic, or has hundreds of names in it, hire a professional. Six hundred dollars to make your book genuinely usable is one of the better deals in publishing.

If you’re earlier in the process, start with structure: our guides to writing a nonfiction book and building a nonfiction book outline will save you indexing time later, because a book with consistent terminology practically indexes itself.

Sources: American Society for Indexing · The Chicago Manual of Style, Ch. 16 · University of Chicago Press indexing chapter (PDF) · Cindex open-source release · MACREX Indexing Program · ASI software directory · Penn State University Press indexing guidelines (PDF) · MIT Press indexing instructions for authors (PDF)