How Many Words Per Hour Is an Audiobook?
The standard figure, a calculator for your own word count, typical lengths by genre, and why the number matters for price and cost.
In this article
Before you make an audiobook, it helps to know how long it will be. Length sets what a narrator charges, what the stores price it at, and how long the work takes.
An audiobook runs about 9,300 words per finished hour, which is about 155 words a minute. Divide your word count by 9,300 to get the length in hours: a 90,000-word novel comes out at about 9 hours 40 minutes. That figure comes from ACX, Audible’s production platform. Below you’ll find a calculator for your own book, typical lengths by genre, and how length affects price and cost.
The standard: 9,300 words per finished hour
ACX’s help pages say: “On average, most performers narrate about 9,300 words per hour.” To estimate your audiobook’s length, divide your book’s word count by 9,300. ACX does the same sum for you when you create a title and enter your word count.
A finished hour means an hour of the final, edited audio, not an hour of recording time. It’s the unit narrators charge by and stores use for length.
Not everyone uses the same number. Voices by INaudio, the biggest audiobook distributor, says “9,000 words equal approximately one hour of finished audio”. The difference is small (about 20 minutes on a 90,000-word book), but it’s why two calculators can give slightly different answers.
Calculate your audiobook’s length
Enter your word count and choose a reading speed. Typical is 155 words a minute, ACX’s figure.
The credits figure is for Audiobook Generator’s Standard quality, at about six characters a word.
How long is an audiobook by genre?
Typical word counts vary by genre. Using 9,300 words per hour:
| Genre | Typical word count | Audiobook length |
|---|---|---|
| Middle grade | 20,000 to 55,000 | 2 h 10 min to 5 h 55 min |
| Young adult | 55,000 to 80,000 | 5 h 55 min to 8 h 35 min |
| Adult fiction | 80,000 to 90,000 | 8 h 35 min to 9 h 40 min |
| Memoir | 80,000 to 90,000 | 8 h 35 min to 9 h 40 min |
| Science fiction and fantasy | 100,000 to 115,000 | 10 h 45 min to 12 h 22 min |
The word counts are common industry ranges from Writer’s Digest, not store rules. Your own book’s count is what matters.
Why the same book can run longer or shorter
9,300 words per hour is an average. These things move it:
- The narrator’s pace. Some narrators read faster than others, and a calm literary novel is read more slowly than a fast thriller.
- Dialogue and pauses. A book full of short lines of dialogue has more pauses than one of long paragraphs.
- Credits and extras. Opening and closing credits, chapter titles and any author’s note add a minute or two each.
- Footnotes and back matter. Whatever you cut from the audio (indexes, references, image captions) makes it shorter than the word count suggests. Our guide to preparing your manuscript for AI narration covers what to cut.
- AI voice speed. With AI narration, speed is a setting. ElevenLabs lets you set a voice between 0.7 and 1.2 times its normal speed, and Google Play’s auto-narration starts at 1.00x and can be adjusted per narrator, character or phrase.
Why length matters
It sets the price on Audible
Audible sets the price of ACX audiobooks itself, and length is one of the main inputs. ACX’s own figures show the ranges Audible prices have fallen in:
| Length | Price range on Audible |
|---|---|
| Under 1 hour | Under $7.40 |
| 1 to 3 hours | $5.55 to $13.20 |
| 3 to 5 hours | $7.55 to $15.55 |
| 5 to 10 hours | $11.15 to $20.65 |
| 10 to 20 hours | $12.95 to $24.90 |
| Over 20 hours | $16.40 to $32.95 |
Spotify for Authors suggests list prices by length too: $15 to $25 for a 6 to 10 hour book, and $17.50 to $25 for 10 to 15 hours. Where you set your own price, use these as a guide.
It sets the cost of narration
Human narrators charge per finished hour, so a 10-hour book costs ten times their hourly rate. ACX also estimates the work behind each finished hour at about 6.2 hours: 2 hours recording, 3 hours editing and 1.2 hours reviewing. That’s why a 10-hour audiobook takes a narrator weeks, not days. Our guide to how much it costs to make an audiobook has the full numbers.
With AI narration, cost follows the text instead. An AI audiobook generator charges by the characters it reads, so a 90,000-word book costs the same whether the voice reads it quickly or slowly.
It sets how you split the files
Stores limit how long each file can be. ACX asks for files of 120 minutes or less, and Spotify for 2 hours or less, so a very long chapter has to be split. Most books never get near this, because the usual chapter runs 10 to 30 minutes.
How many pages is an hour of audio?
A printed page holds roughly 250 to 300 words, so an hour of audio covers about 30 to 37 pages. Page counts vary a lot with the trim size and font, so word count is the more reliable way to estimate.
FAQ
How many words per hour is an audiobook?
About 9,300 words per finished hour, according to ACX. That’s about 155 words a minute. Voices by INaudio uses 9,000 words per hour.
How long is a 100,000-word audiobook?
About 10 hours 45 minutes, at 9,300 words per hour. At 9,000 words per hour it’s about 11 hours.
How long is a 50,000-word audiobook?
About 5 hours 23 minutes at 9,300 words per hour.
How many words per minute do audiobook narrators read?
About 155 words a minute on average, based on ACX’s 9,300 words per hour. Faster narrators read 165 to 170 words a minute, slower ones about 140.
How long does it take to record one finished hour?
ACX estimates about 6.2 hours of work for each finished hour: recording, editing and reviewing. AI narration skips the recording and most of the editing, so the time goes into listening back and fixing.
Do AI voices read faster than humans?
Not necessarily. AI voices read at a natural pace by default, and most tools let you change the speed. Set it once for the whole book so every chapter sounds the same.
Ready to hear your book?
Now you know how long your audiobook will be, you can hear how it sounds. Upload your manuscript and narrate your first chapter free.
Philip Ghezelbash is the founder of Audiobook Generator and the author of The Stoic Body, which has sold over 10,000 copies on Amazon. He writes about making, publishing and selling audiobooks.
Keep reading
Do Audiobooks Need an ISBN?
Which stores ask for an ISBN, which give you one free, what one costs, and when it’s worth buying your own.
Philip Ghezelbash··6 min read
Audiobook File Formats: MP3 vs M4B and Which to Use
What MP3 and M4B are, which one each store accepts, and the exact specs your audiobook files need to pass.
Philip Ghezelbash··6 min read
What Size Should an Audiobook Cover Be?
The one size that works everywhere, each store’s rules, and how to turn your ebook cover into a square that still reads at thumbnail size.
Philip Ghezelbash··4 min read