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Audiobook Length Calculator

A 50,000-word book makes about 5 hours 23 minutes of finished audio at the standard narration pace of 155 words per minute — the ACX rule of 9,300 words per finished hour. An 80,000-word novel runs about 8 hours 36 minutes, and 100,000 words about 10 hours 45 minutes. Slow narration adds about a fifth; brisk narration trims it.

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By the Infinite Library editorial team. Every number on this page comes from the same arithmetic as the calculator; the assumptions are stated below it.

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Common lengths:

Standard is the ACX planning figure of about 9,300 words per finished hour.

5 h 23 min≈ 5.4 finished hours

50,000 words narrated at 155 words per minute — the ACX estimate of 9,300 words per finished hour

Slow · 130 wpm
6 h 25 min
Standard · 155 wpm
5 h 23 min
Brisk · 180 wpm
4 h 38 min
ACX estimate · 9,300 words per hour
5.4 finished hours
Words per finished hour at this pace
9,300

Finished audio — the edited final recording, the unit narrators are paid by and retailers price by. Recording and editing take longer.

Finished hours for common word counts

Finished audio — the edited final recording. Standard is the ACX planning estimate of 9,300 words per finished hour (155 words a minute); slow and brisk bracket real narrators.
WordsSlow · 130 wpmStandard · 155 wpmBrisk · 180 wpm
20,0002 h 34 min2 h 9 min1 h 51 min
30,0003 h 51 min3 h 14 min2 h 47 min
40,0005 h 8 min4 h 18 min3 h 42 min
50,0006 h 25 min5 h 23 min4 h 38 min
60,0007 h 42 min6 h 27 min5 h 33 min
70,0008 h 58 min7 h 32 min6 h 29 min
80,00010 h 15 min8 h 36 min7 h 24 min
90,00011 h 32 min9 h 41 min8 h 20 min
100,00012 h 49 min10 h 45 min9 h 16 min
120,00015 h 23 min12 h 54 min11 h 7 min

The rule of thumb: 9,300 words per finished hour

Audiobook producers estimate length from the manuscript before a word is recorded, and the figure the industry plans around is about 9,300 words per finished hour — the estimate ACX, Audible's production marketplace, gives authors and narrators. It works out to roughly 155 words per minute, which is the standard pace in the calculator. A finished hour is an hour of the final, edited audio, with the retakes, breaths and long pauses cut: the unit narrators are paid by and retailers price by.

Divide your word count by 9,300 and you have your finished hours. 50,000 words is about 5.4 hours; 80,000 words about 8.6; 100,000 words about 10.8. Audible sets audiobook prices by finished length in bands, so a manuscript that lands near the edge of a band is worth knowing about before you record.

Slow, standard and brisk

Narrators do not read at one speed. Dialogue-heavy fiction with distinct character voices runs slower, because each change of voice needs a beat and the pauses between lines are part of the performance. Children's books, and anything meant to be followed along with on the page, run slower still. The slow setting at 130 words per minute covers that end. Plain non-fiction — a business book, a how-to — is usually read briskly, and the brisk setting at 180 words per minute covers that end. Most novels and memoirs land near the standard 155.

The spread matters more than it looks. At 100,000 words, slow narration produces about 12 hours 49 minutes and brisk narration about 9 hours 16 minutes — three and a half hours of difference in the final product, from the same text. If you are narrating yourself, record a chapter, time it, and enter your own pace in the calculator to project the whole book.

What the finished hours mean for production

A finished hour is not an hour of work. A narrator reads in sessions and re-records fluffed lines, and then the audio is edited, mastered and checked chapter by chapter, so recording and editing take a good deal longer than the finished length. That is why professional narration is priced per finished hour rather than per word, and why an 80,000-word novel — about eight and a half finished hours — is a real production rather than a weekend.

If the book is going to retail, the finished length also decides its price band, and listeners judge value by the hours on the listing. A 20,000-word novella at 2 hours 9 minutes and a 120,000-word epic at 12 hours 54 minutes are different products, and listeners of each expect the length that matches the genre — the same ranges our novel length guide sets out in words.

Narrating your book in Bindery

Bindery turns a finished book into its audiobook edition without a studio. Choose one of three house narrators, or clone your own voice from about thirty seconds of audio and let the book be read in it — in any of 74 languages, so a translated edition can be narrated in its own language too. The first chapter plays free on the book's public page, which is where most listeners decide whether to buy; the rest is sold from the same storefront, and authors keep 80% of every audiobook sale. The same page sells the ebook and the paperback, with about 95% ebook royalty and an author-set print royalty.

The audiobook page walks through the narrators, voice cloning and languages; the words to pages calculator covers the print edition of the same book, and the reading time calculator the silent-reading hours.

Frequently asked questions

How many hours is a 50,000-word audiobook?

About 5 hours 23 minutes at the standard narration pace of 155 words per minute (9,300 words per finished hour). Slow narration at 130 words per minute makes it about 6 hours 25 minutes; brisk narration at 180 about 4 hours 38 minutes.

How many words are in one hour of audiobook?

About 9,300 words per finished hour is the planning estimate ACX gives — roughly 155 words per minute. Slow narrators cover about 7,800 words an hour, brisk ones about 10,800.

How long is an 80,000-word audiobook?

About 8 hours 36 minutes at 155 words per minute. At 130 words per minute it runs about 10 hours 15 minutes; at 180 about 7 hours 24 minutes.

How many words is a 10-hour audiobook?

About 93,000 words at the standard 9,300 words per finished hour — a full-length novel. An 8-hour audiobook is about 74,000 words; a 12-hour one about 112,000.

What is a finished hour?

One hour of the final, edited audiobook — retakes, mistakes and long pauses removed. Narrators are usually paid per finished hour and retailers price by it, which is why estimates are given in finished hours rather than recording time.

Can I narrate my own audiobook in Bindery?

Yes. Bindery clones your voice from about 30 seconds of audio and reads the book in it, or you can pick one of three house narrators; either way it works in 74 languages, the first chapter plays free on the book's page, and you keep 80% of audiobook sales.

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Bring a finished manuscript or write one with Claude, then narrate it in Bindery: three house voices or your own, 74 languages, the first chapter free for every listener, and 80% of sales to you. Free to start, no credit card.

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