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Calculate the estimated reading time of an article using JavaScript

Michael Burrows on January 08, 2021

You’ve probably seen displayed on websites like Medium an estimated reading time. This metric helps users decide if they read the article immediate...

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Brian Barbour • Mar 1 '23

Awesome! Thanks for sharing.

Tiago Rangel • Jan 14

Thanks!

With the help of ChatGPT, I created a reading time estimator even more precise than this based on the code you provided. Here's the code if you wanna use it:

            function readingTime(text) {
              const averageWPM = 250;

              const words = text.trim().split(/\s+/);

              const adjustedText = text.replace(/(.)\1+/g, '$1');

              const adjustedSentences = adjustedText.replace(/([.!?])\s*\1+/g, '$1');

              const adjustedCharCount = adjustedSentences.length;

              const adjustedWords = adjustedSentences.trim().split(/\s+/);
              const adjustedWordCount = adjustedWords.length;
              const averageWordLength = adjustedCharCount / adjustedWordCount;

              const adjustedTime = (adjustedCharCount / averageWPM) * (averageWordLength / 5);

              const formattedAdjustedTime = adjustedTime > 1 ? Math.round(adjustedTime) + " min" : "Less than 1 min";

              return formattedAdjustedTime;
            }

David Dal Busco • Jan 8 '21

Interesting share @michaelburrows.xyz 👍

The constant value 225 for wpm is a known general accepted value or what's its source?

Bhupesh Singh Nikhurpa • Jan 8 '21

According to a speed-reading test sponsored by Staples as part of an e-book promotion, here are the typical speeds at which humans read, and in theory comprehend, at various stages of educational development :

Third-grade students = 150 words per minute (wpm)
Eighth grade students = 250 wpm
Average college student = 450 wpm
Average "high-level exec" = 575 wpm
Average college professor = 675 wpm
Speed readers = 1,500 wpm
World speed reading champion = 4,700 wpm
Average adult = 300 wpm

David Dal Busco • Jan 8 '21

Excellent! Thanks for the metrics 👍.

Proven numbers and code snippets, it seems that I have no more excuses to not add such information to our dashboard 😉.

Reza Majidi • May 2 '22

Medium is using 265 WMP for calculation.

medium.com/blogging-guide/how-is-m...

Tip Season • Sep 5 '22

Hey Michael, Thanks for this tutorial. Recently made a tool to calculate time to read a post. Sharing to help someone trying to estimate time for their blogs.

tipseason.com/reading-time-calculator

rabiu-dev • Apr 26 '21

I know the split() method splits a string into an array of substrings. But what does the parameter inside this split method do in this code?? split(/\s+/)