Eons ago, a couple of Medium engineers got fed up. They were sick of having to scroll all the way down the page to see how long a story was. It was wearing out their trackpad, it was making their fingers sore, and they figured there must be a better way. So they sat down and devised a simple formula, and the Medium read time was born.
With the widespread adoption of this feature across the internet, we decided to shed some light on exactly what goes in to our read time calculation.
Read time is based on the average reading speed of an adult (roughly 275 WPM). We take the total word count of a post and translate it into minutes. Then, we add 12 seconds for each inline image. Boom, read time.
Lately, we have seen more and more long form stories containing a ton of images. With our release of image grids, we expect even more of these types of essays.
Our original read time calculation was geared toward “slow” images, like comics, where you would really want to sit down and invest in the image. This resulted in articles with crazy big read times. For instance, this article containing 140 images was clocking in at a whopping 87 minute read. So we amended our read time calculation to count 12 seconds for the first image, 11 for the second, and minus an additional second for each subsequent image. Any images after the tenth image are counted at three seconds.
You might see this change reflected across the site. Keep in mind that our estimated read time is just that: an estimation. You might finish a story faster or slower depending on various factors such as how many children or cats you have, your caffeine/alcohol intake, or if you’re a time-traveler from the future and already read that story. We just want to give you a ballpark figure so you can decide whether you have time to read one more story before the bus comes, or if you should bookmark it for later.
We aren’t done with read time yet. In the future, we’d like to tailor it to your reading speed, account for the complexity of an article, and add support for other languages. We’ll be sure to let you know about these changes as they happen.