How It Works
Why Audiobook Lengths Differ Between Shops, and Which Is True
Audiobook lengths can differ by minutes or hours between shops. Here is why the numbers change, what is counted in them and how to check your edition.
The same recording can show slightly different hours in different shops, because each store formats, rounds and counts the delivered audio package in its own way. A gap of a few minutes is usually that. A gap of an hour or more usually means the two listings are not the same recording at all.
So, here is the rule I would use. Match the narrator, publisher, release year, identifier and abridgement status first, and treat the hours as supporting evidence. If those fields match, a small difference in hours is nothing to worry about. If any of them differ, you are looking at two different audiobooks.
How each store shows the length
Stores do not even write the number the same way. Real listings show it.
- Audible US shows hours and minutes. Stephen King's The Stand, read by Grover Gardner for Random House Audio in 2012 and listed as unabridged, shows 47 hrs and 47 mins.
- Apple Books uses a clock format. A listing for H, narrated by Hugues Martel, shows 14:53.
- Google Play Books shows hours and minutes again. The same Grover Gardner recording of The Stand appears there at 47 hr 47 min.
- Spotify shows hours and minutes and also lists chapter durations. Its Project Hail Mary listing reads 15 hr 4 min, with single chapters shown at lengths such as 58 min 35 sec.
- Library records can keep the seconds. The New York Public Library lists The Reservation with a duration of 06:44:16, and Brooklyn Public Library records One Day at 11 hr, 58 min, 17 sec.
So, a retail page that rounds to the minute and a library page that keeps the seconds can differ without either being wrong. Two numbers written in two formats are not a disagreement yet.
Where the number comes from
The figure is supplied or calculated when the audiobook is distributed. Each shop is not timing the audio again after it arrives. The published documentation I would point you to says this in a few different ways.
Spotify's metadata guide says approximate runtime is optional, and that Spotify calculates the actual duration while it processes the uploaded audio. ACX, the marketplace many independent audiobooks are produced through, says the length on a title profile is calculated from the word count the producer supplies, and it estimates finished length at about 9,300 words per hour in its production guide. Apple's audiobook specification treats a title as audio files plus metadata, with chapter timing measured to less than a second. OverDrive, which supplies many library apps, says its title metadata comes from the publisher.
Those are different systems with different rules. None of them says every store measures the same way, so I would not assume one universal process. What it does tell you is that a store is displaying a number it was handed, formatted its own way.
What sits inside the total
The listed length is the length of the delivered package, and the package can hold more than the story.
ACX requires an opening credit naming the title, author and narrator, and a closing credit. The upload workflow described in a Findaway Voices how-to separates opening credits, front matter, body and back matter, and shows a total built from the uploaded files.
You can see this on real listings. A Spotify listing for a Project Hail Mary summary itemizes a 10 second opening credit, an introduction and a disclaimer inside its total. Apple lists The Godfather, 50th Anniversary Edition, with an introduction, a note and an afterword under one audiobook length. Interviews and bonus material can ride along too, as in Alison Larkin's Jane Austen recordings.
No source I have says every store counts credits and extras in exactly the same way. So, when the extras matter to you, open the edition description and the chapter list and see what is in there.
Re-releases and disc formats
A sound clean-up alone may leave the runtime nearly unchanged. New bonus material, different edits or a new narration can change it.
Apple Books gives two examples of re-released titles. It describes Rebound as previously released and improved for sound quality, at 09:20. It describes The Big Game, Volume 1 as a third and final edition with new bonus material, at 01:03. The words "new edition" or "bonus material" in a description are a reason to check the hours against the edition you want.
Discs are a separate matter. CD and MP3-CD packaging changes how the audio is split across discs, not the performance. Blackstone lists The Download in Library CD and MP3 CD formats with one runtime, 14.18 Hours. Count the discs if you like, but the disc count is not a different recording.
One publisher page shows why each record is read on its own. Hachette Australia's page for David Suchet's Complete NIV Audio Bible shows several format and edition records with different runtimes, among them 11hr 14m, 13hr 23m and 21hr 51m. Read one record at a time and never average them.
When a big gap means a different recording
A difference of an hour or more is a cue to compare the identity fields. These three cases show it.
Project Hail Mary. Apple Books Australia lists about 16 hours 10 minutes for Ray Porter's recording from Audible Studios, released May 4, 2021. A Spotify listing shows 15 hr 4 min for David Garmark, released February 7, 2023. The narrators and dates differ, so these are two recordings, not one recording shown two ways.
Dune. SFFaudio, a fan-run site, compares several recordings: a George Guidall recording at about 24 hours, a Scott Brick recording at about 27 hours and an ensemble recording at about 21 to 22 hours. Treat those as SFFaudio's approximate figures. The point stands either way: different narrators, different publishers, different audiobooks.
Harry Potter and the Deathly Hallows. Jim Dale's recording is listed on Google Play at 21 hr 36 min. A 2026 full-cast edition is described at 20 hours 30 minutes in a New York Times audio listing. One narrator against a full cast is a different production, whatever the hours say. If you are choosing between narrators on this series, the shelf page on Harry Potter, Dale or Fry is the place to start.
11/22/63. This is the closest thing to a same-recording spread. Audible UK lists the Craig Wasson recording at 30 hrs and 40 mins as of October 1, 2026. The full length story for that title lives on the 11/22/63 audiobook length page.
The under-one-minute check
When two listings disagree, go down this list in order.
- Match the narrator or cast.
- Match the publisher or production company.
- Match the release year or date.
- Match the ISBN, ASIN, Audible product ID or OverDrive identifier.
- Confirm both say unabridged, or both share the same abridgement status.
- Compare the title wording and the format: download, CD, MP3-CD, library edition or full cast.
If all six match, a small runtime gap is consistent with rounding, formatting or package presentation. If any one differs, treat them as different recordings until the publisher confirms otherwise.
So, which number is true? The one on the listing for the exact recording you are buying, borrowing or streaming. Use that store's figure for planning your time, and compare the identity fields when two stores disagree.
If you are looking at a Libro.fm listing, do the same thing: compare its narrator, publisher, release date and identifier with another store before you decide the two are the same audiobook.
Audiobook length questions
Short answers to four length questions.
Why does the same audiobook show a different length in different shops?
Each store formats and rounds the length it was given in its own way, and some count credits or extras that others describe differently. A library record can keep the seconds while a retail page shows only hours and minutes. A gap of an hour or more usually means a different recording.
How many hours is a 300 page book on Audible?
ACX estimates finished length at about 9,300 words per hour, so divide the book's word count by 9,300. Pages hold different numbers of words from book to book, so a page count gives only a rough guess. The listing for the exact recording will show the real figure.
What is the longest audiobook on Audible?
The answer changes as titles are added, and you can sort by length in the store to see the current longest. For a sense of how long a listed title can run, The Stand with Grover Gardner shows 47 hrs and 47 mins on Audible US.
Which length is true when two shops disagree?
The one on the listing for the exact recording you are getting. Run the six checks above, and if narrator, publisher, release date, identifier and abridgement status all match, the small gap is formatting.
Where to go next
If the hours are what you are really weighing, the 11/22/63 audiobook length page shows the checks at work on a very long title. And if the narrator is the part you are unsure about, the page on the Mere Christianity audiobook narrator is a good one to read next.
By Cal Hewitt. Published .