Free tool
How long your book takes at any playback speed, what the speed-up saves, and when you will finish at your daily pace.
Your audiobook
Playback speed
At 1.5× speed
You save 2 hr 48 min against the 8 hr 24 min runtime.
finished in 8 days
| Speed | Listening time | Time saved |
|---|---|---|
| 1× | 8 hr 24 min | – |
| 1.25× | 6 hr 43 min | 1 hr 41 min |
| 1.5× | 5 hr 36 min | 2 hr 48 min |
| 1.75× | 4 hr 48 min | 3 hr 36 min |
| 2× | 4 hr 12 min | 4 hr 12 min |
| 2.5× | 3 hr 22 min | 5 hr 2 min |
| 3× | 2 hr 48 min | 5 hr 36 min |
Playback speed divides runtime directly: a 9-hour book at 1.5× takes 6 hours. Audiobook narrators record at roughly 150 to 160 words per minute, a pace chosen for clarity rather than efficiency, which is why moderate speed-ups sound natural. Comprehension research finds the practical ceiling sits somewhere before 2× for material you have never seen, and higher for material you are reviewing.
The finish estimate divides the sped-up runtime by your daily listening minutes. Forty-five minutes a day, the length of a typical commute both ways, finishes a standard novel inside two weeks at 1.5×.
Working from a manuscript or a book with no audiobook? At standard narration pace, word count converts to listening time like this:
| 30,000 words | ≈ 3 hr 15 min | A novella |
| 50,000 words | ≈ 5 hr 25 min | A short novel |
| 80,000 words | ≈ 8 hr 35 min | A typical novel |
| 100,000 words | ≈ 10 hr 45 min | A long novel |
| 150,000 words | ≈ 16 hr 10 min | A dense non-fiction book |
| 250,000 words | ≈ 26 hr 50 min | A full textbook |
Based on 9,300 words per narrated hour. Your own PDFs and EPUBs convert on the same arithmetic: PDF to audiobook or EPUB to audiobook.
Most regular listeners settle between 1.25× and 1.75×. Narrators record deliberately slowly, around 150 to 160 words per minute, so a modest speed-up sounds natural rather than rushed. The practical rule: familiar or light material tolerates higher speeds, while dense or technical material is worth keeping near 1× on first listen.
Research on accelerated speech finds comprehension holds up well through moderate speed-ups and begins to degrade as speech approaches double rate, with the effect strongest on unfamiliar, information-dense material. For a novel you are enjoying, 2× is usually fine after some adjustment. For a textbook chapter you have never seen, it usually is not.
A typical trade audiobook runs 8 to 12 hours, which corresponds to a 70,000 to 110,000 word book narrated at standard pace. Epic fiction can exceed 20 hours, and a 400-page textbook converted to audio commonly lands between 15 and 25 hours, which is exactly why chapter navigation and playback speed matter more for textbooks than for novels.
Standard audiobook narration covers roughly 9,000 to 9,600 words per hour, based on the industry-typical 150 to 160 words per minute. That is the constant this calculator's reference table uses: an 80,000 word manuscript becomes roughly 8.5 hours of audio at 1× speed.
Yes, by converting the book you own into an audiobook first. Audionarrator turns PDFs and EPUBs into chapter-aware audiobooks with playback speed from 0.75× to 2×, resume across devices, and per-chapter MP3 downloads. The first chapter is free at any length, so you can test your preferred speed on your own material.
The books with no audiobook are the ones this calculator can't help, until you convert them. Chapter-aware audio from any PDF or EPUB, playback from 0.75× to 2×, first chapter free.