In depth
Audiobook length calculator: how it works
An audiobook length calculator answers the first question authors ask about audio: how many hours will my book be? This one works from the producer's side, from the words in your manuscript and the pace of the narration, rather than from a listener's playback speed.
Enter a word or page count and pick a pace, and the finished running time appears with the average chapter length, the page count at 250 words a page and the character count. The pace defaults to 155 words a minute, the same figure the studio uses to estimate running time.
Word count to audiobook length: the 9,300 words-per-hour rule
The usual rule of thumb for turning word count to audiobook length is about 9,300 words per finished hour, which is 155 words a minute. Divide your word count by 9,300 and you have the hours.
At that pace, a 7,500-word short story runs about 48 minutes, a 30,000-word novella about 3 hours 14 minutes, a 90,000-word novel about 9 hours 41 minutes and a 180,000-word epic fantasy about 19 hours 21 minutes. The audiobook length calculator above does the same sum for any number you type.
How long is an audiobook for a 300 page book?
Start from the page count. At 250 words a page, 300 pages is about 75,000 words, which is roughly 8 hours 4 minutes at the average pace, anywhere from 7 hours 21 minutes (brisk) to 8 hours 56 minutes (relaxed).
Printed pages vary a lot, though. A dense paperback page can hold 300 words or more, and 300 of those pages is about 90,000 words, or 9 hours 41 minutes. Large type, short lines and lots of dialogue push the other way. Whenever you can, start from the word count, which your editor gives you exactly.
Audiobook words per hour by genre and pace
Audiobook words per hour aren't fixed. Narration usually sits around 150 to 160 words a minute, or 9,000 to 9,600 words an hour, but the book shapes it. Dialogue-heavy chapters run longer because of the small pauses between speakers; children's books, poetry and dense non-fiction are often read more slowly; a fast thriller can carry a brisker pace.
The calculator's relaxed setting, 140 words a minute, fits about 8,400 words in an hour, and brisk, 170 words a minute, about 10,200. With AI narration, pace comes from the voices you cast and the direction you give them, so the best check is to generate one chapter and scale up from its real length.
How many hours is an audiobook, on average?
How many hours is an audiobook? It depends almost entirely on the word count. Many adult novels land between 70,000 and 100,000 words, which at the average pace is about 7 hours 32 minutes to 10 hours 45 minutes. Novellas come in at a few hours, and long fantasy or historical sagas can pass 20.
That's why an average across all audiobooks doesn't tell you much about yours. Your word count does, and the audiobook length calculator turns it into hours in a second.
Listening time at 1.25x, 1.5x and 2x
Many listeners speed up playback. Listening time is the finished length divided by the speed. A 100,000-word book that runs 10 hours 45 minutes takes about 8 hours 36 minutes at 1.25x, 7 hours 10 minutes at 1.5x and 5 hours 23 minutes at 2x. A 90,000-word novel at 9 hours 41 minutes drops to about 7 hours 45 minutes, 6 hours 27 minutes and 4 hours 50 minutes.
Stores list the finished length, not the sped-up one, so plan production, chapter lengths and file sizes from the real running time.
From length to cost and chapters
Once you know the hours, the audiobook cost calculator turns the same word count into credits and shows which plan covers it. When the audio is made, an M4B audiobook keeps every chapter as a marker in one file, so a long book stays easy to navigate. To see how the studio gets from manuscript to finished audio, read how it works on the home page.
