Audiobook Speed Calculator
Enter an audiobook's length at normal (1x) speed and your playback speed to see your actual listening time, how much time you save, and when you will finish.
Your results
Compare all speeds
| Speed | Listening time | Vs 1x | Saved |
|---|
How it works
Actual listening time is the book's 1x length divided by your playback speed. Time saved versus normal speed is the length multiplied by (1 − 1/speed).
Example: a 10-hour audiobook at 1.5x takes 6 hr 40 min — that is 3 hr 20 min (33.33%) less than at normal speed. At 2x it takes 5 hr, saving 5 hr (50.00%). At 1 hour of listening per day, the 1.5x version (6 hr 40 min) takes 7 days to finish.
Frequently asked questions
How is audiobook listening time calculated?
Divide the book's length at normal speed by your playback speed: actual time = duration / speed. A 10-hour audiobook at 1.5x takes 10 / 1.5 = 6 hr 40 min. Time saved versus 1x is duration x (1 - 1/speed): 10 x (1 - 1/1.5) = 3 hr 20 min, which is 33.33% of the original length.
Does listening at 2x hurt comprehension?
Research on time-compressed speech generally finds little to no comprehension loss up to about 1.5x for most adult listeners; beyond 2x, comprehension tends to drop, and results vary by person and material. This is general information, not medical advice. A common approach is to start at 1.25x-1.5x and raise it gradually.
Which playback speeds are supported?
One-tap presets cover 0.75x, 1x, 1.25x, 1.5x, 1.75x, 2x, 2.5x and 3x, and you can type any custom speed from 0.25x to 4x.
How is the finish date estimated?
The calculator adds your actual listening time to your start date and time. Example: starting October 8, 2026 at 9:00 AM, a 10-hour book at 1.5x (6 hr 40 min of listening) finishes the same day at 3:40 PM. If you enter daily listening minutes, it rounds up to whole days instead: 6 hr 40 min at 60 minutes per day takes 7 days.
Can I use this for podcasts, lectures, or video courses?
Yes. The math is identical for anything with a stated length - podcasts, lectures, courses, or videos - as long as you know the total duration at normal speed.
Why does 0.75x show extra time instead of saved time?
Speeds below 1x make listening longer, not shorter. A 10-hour audiobook at 0.75x takes 13 hr 20 min, which is 3 hr 20 min extra compared with normal speed.
Free tool by NRTechStudio