Playback Speed Calculator
See how long an audiobook, podcast, lecture or video takes at 1.25×, 1.5×, 2× or any speed, how much time you save, and the speed needed to finish in a target time.
| Speed | Listening time | Time saved |
|---|---|---|
| 1× | 10:00:00 | 0:00:00 |
| 1.1× | 9:05:27 | 0:54:33 |
| 1.25× | 8:00:00 | 2:00:00 |
| 1.5× | 6:40:00 | 3:20:00 |
| 1.75× | 5:42:51 | 4:17:09 |
| 2× | 5:00:00 | 5:00:00 |
| 2.5× | 4:00:00 | 6:00:00 |
| 3× | 3:20:00 | 6:40:00 |
Listening faster is the easiest way to get through a long audiobook, a podcast backlog or a recorded lecture. This calculator shows the real listening time at any playback speed, how much time you save, and — if you have a deadline or a commute of known length — the speed you would need to finish in time. It works for any player, from audiobook and podcast apps to video sites.
How to use this tool
- Enter the length at normal speed as h:mm:ss, mm:ss, minutes, or something like "2h 15m".
- Pick a speed, or choose Custom for any value from 0.1× to 16×.
- Optionally enter the time you have to see the speed needed.
- Compare common speeds in the table.
Formula
new length = original length ÷ speed; time saved = original − new length; speed needed = original ÷ time available
Speed is a multiplier of normal playback: 1.5× plays 1.5 seconds of content every second. The saving as a share of the original is 1 − 1 ÷ speed, so 1.5× saves 33.3% and 2× saves 50%.
Example
A 10-hour audiobook at 1.5× takes 10 ÷ 1.5 = 6 hours 40 minutes, saving 3 hours 20 minutes. To fit a 60-minute lecture into a 45-minute commute you need 60 ÷ 45 = 1.33×.
Frequently asked questions
Which speed is easiest to follow?
Many listeners find 1.25× to 1.5× comfortable for narration and talks within a few days; 2× needs practice and suits familiar or slow speakers. Dense technical content is often better at normal speed.
Why does 2× not save twice as much as 1.5×?
Because the saving is 1 − 1 ÷ speed: 1.5× saves a third, 2× saves a half, 3× saves two thirds. Each extra step saves less.
Can I change the speed of a file I have?
Yes — use the audio speed changer or the video speed changer to save a sped-up copy.
Last updated:
Page address with these inputs: https://kakao.mobile/tools/playback-speed-calculator/
Cite or embed this tool
kakaoCalc. (2026, November 8). Playback Speed Calculator. https://kakao.mobile/tools/playback-speed-calculator/
“Playback Speed Calculator.” kakaoCalc, 8 Nov. 2026, kakao.mobile/tools/playback-speed-calculator/.
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