How long will it be?

Professional narration averages about 150–160 words per minute, so a common planning figure is about 9,300 words per finished hour. An 80,000-word novel is roughly 8.5–9 hours; a 50,000-word self-help book about 5.5 hours. Use the audiobook calculator for your manuscript.

How production is priced

Narration and production are usually quoted per finished hour (PFH) — per hour of the final audiobook, not per hour of studio time. Recording, editing, proofing (listening against the text) and mastering together take several hours of work for every finished hour. Some narrators work on a royalty-share basis instead of an upfront fee.

Retail technical requirements

ACX, the production marketplace for Audible, publishes strict requirements that other retailers broadly mirror:

  • MP3 at a constant bit rate of 192 kbps or higher, 44.1 kHz sample rate.
  • Each file is one chapter or section, no longer than 120 minutes.
  • Consistent mono or stereo throughout.
  • RMS loudness between −23 dB and −18 dB; peaks no higher than −3 dB; noise floor below −60 dB RMS.
  • About 0.5–1 second of room tone at the start of each file and 1–5 seconds at the end.
  • Separate opening and closing credits, and a 1–5 minute retail sample.

Preparing the script

  • Remove or adapt visual elements: tables, footnotes, image captions and "see page 42" references.
  • Create a pronunciation guide for names, places and invented words.
  • Decide what to do with front and back matter — dedications usually stay; indexes go.
  • Consider a downloadable PDF companion for charts, maps or worksheets.

Cover art

Audiobook covers are square — commonly at least 2400 x 2400 px — so your print cover needs a square adaptation with the title readable at thumbnail size.