Audiobook Speed Calculator
Find your adjusted listening time at any playback speed, or reverse-lookup the speed needed to finish by a target time.
Audiobook Length (at 1x)
Playback Speed
Reverse Lookup: Target Time
How fast do I need to play it to finish in this much time?
Speed Comparison Table
| Speed | Time | Saved |
|---|---|---|
| 1x | 10h 30m | -- |
| 1.25x | 8h 24m | -2h 6m |
| 1.5x | 7h | -3h 30m |
| 1.75x | 6h | -4h 30m |
| 2x | 5h 15m | -5h 15m |
| 2.25x | 4h 40m | -5h 50m |
| 2.5x | 4h 12m | -6h 18m |
| 2.75x | 3h 49m | -6h 40m |
| 3x | 3h 30m | -7h |
How Audiobook Speed Calculations Work
Adjusted listening time is simply the audiobook's original (1x) duration divided by the playback speed multiplier: adjusted time = original length ÷ speed. A 10-hour audiobook played at 2x finishes in 5 hours; at 1.5x it takes about 6 hours and 40 minutes. Most audiobook and podcast apps (Audible, Libby, Spotify, Apple Books) support speeds from around 0.5x up to 3x or higher, with 1.25x–1.75x being the most common "faster but still natural-sounding" range thanks to pitch-correction algorithms.
The reverse lookup solves the same formula for speed instead of time: required speed = original length ÷ target time. This answers questions like "I have a 90-minute commute and an 8-hour audiobook — what speed finishes it in one listen?" If the result exceeds roughly 5x, most playback engines can no longer keep speech intelligible, so the calculator flags it as not realistically achievable.
Private & free — this tool runs entirely in your browser.