Audiobook Speed Calculator: How Long at 1.5× or 2×?

This audiobook speed calculator shows how long an audiobook takes at the speed you listen at, and how much time that saves. A 12-hour-30-minute book takes 8 hours 20 minutes at 1.5×, saving 4 hours 10 minutes; at 45 minutes a day, that is 12 days.

It also starts from where you are in a book, turns the result into a finish date, and works backwards: give it a date, such as the end of a library loan, and it tells you the speed you need.

How to use the audiobook speed calculator

The calculator opens on an example, a 12-hour-30-minute audiobook at 1.5×. Replace it with your own numbers; the results update as you type.

1. Enter the book’s length at 1×

   Use the length the store or your app lists, in hours and minutes. That is the running time at normal speed, whatever speed you listen at.

2. Set your playback speed

   Pick one of the common speeds or type your own, from 0.5× to 3.5× in steps of 0.05.

3. Add your progress, if you have started

   Choose Time and enter your position in the book, or Percent if your app shows how far through you are. The calculator then works on what is left.

4. Say how long you listen each day

   Enter your daily listening time to get the days and a finish date. To finish by a particular day, add it under Finish by, and the calculator gives you the speed that gets you there.

Under the result, a table shows the same book at seven speeds, from 1× to 3×, with the time each one saves. The calculator runs in your browser and keeps your numbers in the page’s address, so Copy link shares them.

How the audiobook speed calculator works

Every number can be checked by hand:

• What is left is the length at 1× minus your position, or the length times the share you haven’t heard. 40% into a 750-minute book leaves 450 minutes.
• Listening time is what is left divided by the speed, rounded to the nearest minute: 750 ÷ 1.5 is 500 minutes, or 8 hours 20 minutes.
• Time saved is the difference between the two: 750 − 500 is 250 minutes, or 4 hours 10 minutes. Below 1×, the difference is time added.
• Days are the listening time divided by your minutes a day, rounded up so the plan never falls short. 500 ÷ 45 is 11.1, so 12 days.
• Finish date counts today as day one. Twelve days from Sunday, November 1, 2026, ends on Thursday, November 12.
• The speed to finish by a date is what is left divided by the minutes you can listen before then, rounded up to the next 0.05×. Ten days at 45 minutes is 450 minutes, and 750 ÷ 450 is 1.67, so 1.7×.

The words-a-minute figures come from narration pace. ACX, Audible’s audiobook-production service, says most narrators record about 9,300 words an hour,¹ which is 155 words a minute. Multiply by the speed: 1.5× is about 233 words a minute and 2× is 310. For comparison, a 2019 meta-analysis of 190 studies put average adult silent reading in English at 238 words a minute for non-fiction and 260 for fiction,² so narration matches it at about 1.55× to 1.7×. Narrators differ, so the calculator lets you change the pace under Adjust the narration pace.

How long is an audiobook at 1.25×, 1.5× or 2×?

These are the calculator’s results for common lengths. As a guide to lengths, an 80,000-word novel runs about 8 hours 36 minutes at ACX’s pace.

The saving grows with the speed but shrinks with each step: going from 1× to 1.5× saves a third of the length, and going on to 2× saves only another sixth.

What speed should you listen to audiobooks at?

There is no single right speed, but there is evidence about where comprehension starts to slip. In a 2022 study in Applied Cognitive Psychology, 231 university students watched two lecture videos at 1×, 1.5×, 2× or 2.5× and were tested right away and a week later. Going from 1× to 1.5× or 2× cost little, but performance fell beyond 2×: the 2.5× group scored worse than the 1× group.³

The lectures ran at about 157 to 166 words a minute at 1×, close to an audiobook narrator, so 2× was about 314 to 332 words a minute. The authors summarize older research on sped-up speech, which put the point where comprehension of audio alone begins to decline at around 275 words a minute,³ about 1.8× for a typical narrator. They also note that their results may differ for harder material or other speech rates, and that a video’s pictures may help viewers keep up in a way audio alone cannot.

What that means in practice:

• Start at a speed that feels easy, then step up. Raise it by 0.1× or 0.25× once a narrator’s voice feels normal, and stop when you notice yourself rewinding.
• Slow down for dense books. A thriller and a book of economics are not the same listen. Audible saves a separate speed for each title in your library, so a slower one for a harder book doesn’t change the rest.⁴
• Know your app’s range. Audible lets you set 0.5× to 3.5×,⁵ and Libby 0.6× to 3×.⁶

Whether listening counts as reading at all is a separate question, and the studies on it are encouraging; we go through them in do audiobooks count as reading?

A worked example: finishing a library loan in time

Say that on Sunday, November 1, 2026, you are 40% into a 12-hour-30-minute audiobook from the library, the loan ends on Tuesday, November 10, and you listen for 30 minutes a day. That leaves 7 hours 30 minutes at 1×, which at 30 minutes a day takes 15 days: five too many.

Enter November 10 under Finish by, and the calculator answers 1.5×. At that speed the rest takes 5 hours of real time, which is exactly 10 days at 30 minutes a day, and you would hear the last chapter on the day the loan ends. If 1.5× feels too fast for this narrator, the other lever is time: at 1.25×, the same 7 hours 30 minutes take 6 hours, which fits in the 10 days at 36 minutes a day.

Tips for finishing more audiobooks

• Plan in real minutes, not book hours. Your commute or walk is fixed; the book’s length shrinks with speed. Put the daily figure where you will see it.
• Use the reverse mode for deadlines. A book club date or a loan that ends turns into one number to set in your app.
• Mix listening and reading. At about 1.5×, an hour of listening covers about as much of a book as an hour of reading. Our reading time calculator gives the length of a print book and its audiobook side by side.
• For a yearly goal, count audiobooks in. The pages per day calculator lets you set aside some of the books left as audiobooks and plans the listening around them.

Track your audiobooks in Omniphile

The calculator gives you a plan; a log shows how it went. In Omniphile, our app for iPhone, iPad and Mac, audiobooks are their own kind of media, tracked by readthrough: each listening session records the position you reached, or your percentage or chapters. Percentage tracking for audiobooks arrived in version 4.5, as listed in the changelog. Audiobooks get their own goals, and a setting can count them toward your Books goals too. Omniphile costs nothing to download and has an optional Premium tier; it runs on iPhone, iPad and Mac, plus Apple Watch with Premium.