Audiobook Length Calculator
Turn a manuscript word count into finished hours, studio time, narration cost and audio file size, with a chapter-by-chapter breakdown. Free and in-browser.
Cross-check
At 9,300 words per finished hour the book runs 8h 36m. Reading the same manuscript aloud at 155 words per minute gives 8h 36m — the two methods agree, so the estimate is stable.
Narration cost
- Up-front fee — 8.6 PFH × 250.00
- 2,150.54
- Total to the narrator
- 2,150.54
- Effective cost per finished hour
- 250.00
4 chapters · 15,000 words
| Chapter | Words | Running time | File size |
|---|---|---|---|
| Prologue | 1,800 | 0h 12m | 16.7 MB |
| Chapter 1 | 4,200 | 0h 27m | 39 MB |
| Chapter 2 | 3,900 | 0h 25m | 36.2 MB |
| Chapter 3 | 5,100 | 0h 33m | 47.4 MB |
Chapter words total 15,000, which is 65,000 away from the manuscript word count above.
Estimates only. 9,300 words per finished hour is a long-standing industry average and is arithmetically the same as narrating at 155 words per minute; dense non-fiction, verse and heavy dialogue all move the real figure. File size uses the exact relationship bitrate × duration ÷ 8, so 192 kbps for one hour is 86.4 MB. Everything is calculated in your browser — nothing is uploaded.
What is the Audiobook Length Calculator?
Audiobook Length Calculator converts a word count into a finished running time using the industry rule of thumb of 9,300 words per finished hour, then cross-checks it against a narration speed in words per minute so you can see whether your two assumptions agree.
- Finished hours from words per finished hour, cross-checked against words per minute
- Studio time estimate from an editable record-and-proof ratio
- Per-finished-hour, royalty-share and hybrid payment models with an effective cost per hour
- File size from bitrate × duration ÷ 8, with a warning when a chapter would break the 170 MB upload limit
- Chapter-by-chapter running times that flag any mismatch with your total word count
How to use the Audiobook Length Calculator
- 1
Enter your manuscript word count and, if you want, adjust the words per finished hour and the narration speed in words per minute.
- 2
Set the studio-hours-per-finished-hour ratio to match how you record and proof.
- 3
Choose an audio bitrate and a payment model, then fill in the rate, retail price and royalty split that apply.
- 4
Paste a chapter list as “Name: word count”, one per line, to get a per-chapter running time and file size.
- 5
Copy the full summary with the “Copy summary” button.
About the Audiobook Length Calculator
Audiobook Length Calculator converts a word count into a finished running time using the industry rule of thumb of 9,300 words per finished hour, then cross-checks it against a narration speed in words per minute so you can see whether your two assumptions agree. Both figures are editable.
It also estimates studio time from a hours-per-finished-hour ratio, prices narration under a per-finished-hour, royalty-share or hybrid deal, works out the audio file size from the bitrate, and breaks the whole book down chapter by chapter with a running time and file size for each.
These are planning estimates, not quotes — real narration speed depends on the material and the narrator. Everything is calculated in your browser and nothing is uploaded.
Frequently asked questions
How many words are in one finished hour of audiobook?
The long-standing industry figure is about 9,300 words per finished hour. That is arithmetically identical to narrating at 155 words per minute, which is why the tool shows both and warns you when the two settings disagree.
How long will my 80,000-word novel be as an audiobook?
At 9,300 words per finished hour, 80,000 words comes to about 8 hours 36 minutes. Dense non-fiction, poetry and heavy dialogue all move that figure, so treat it as a planning number rather than a promise.
How much studio time does one finished hour take?
Two to six studio hours per finished hour is typical once you include recording, punch-and-roll corrections, proofing and mastering. The tool defaults to 2 and lets you set your own ratio.
How do I work out an audiobook file size?
File size is bitrate multiplied by duration, divided by eight. At the common 192 kbps that is about 86 MB per hour; at 64 kbps it is about 29 MB per hour. The calculator applies that formula to the whole book and to each chapter.
What is the difference between per-finished-hour and royalty share?
Per finished hour pays the narrator a fixed rate for every hour of finished audio, whatever the book earns. Royalty share pays nothing up front and splits the royalties instead. The hybrid model does both at a reduced hourly rate.
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