Reading-time math: where "5 min read" comes from

The little badge at the top of every blog post is the answer to a single division problem — but the assumed reading speed varies by 50 percent between publications, your actual speed depends heavily on the subject matter, and the formula misses everything that makes reading slow. Here's the math, and what it doesn't capture.

FOLIOKIT · MAY 2026

The formula in the badge

Almost every reading-time estimator is the same one division:

The only question is which WPM (words per minute) the publication picks. The numbers in use across the web:

225 WPM is roughly the median of the studies on adult silent reading speed for non-fiction text in English. Brysbaert's 2019 meta-analysis of 190 studies put the figure at 238 WPM for typical non-fiction, with a standard deviation wide enough that "between 175 and 300 WPM" covers most adults reasonably well.

Why 225 isn't your reading speed

The badge assumes you're reading uninterrupted, on familiar material, in your strongest language. None of those usually hold. Real-world variables:

Subject matter

Reading speed for fiction in your native language hovers near 260–300 WPM. Reading speed for a textbook on a subject you don't already understand drops to 90–120 WPM, because you're stopping to think. Specialized academic prose slows you to 50–75 WPM. The same brain, the same eyes, a third the speed.

Comprehension target

If you'll be quizzed on it, you re-read sentences. Studies on study-reading (versus pleasure-reading) show roughly 50–70% the speed of casual reading, and that's before notetaking.

Format

Long lines slow people down. So do narrow columns. Newspapers settled on 35–45 characters per line in the 19th century because that's near the empirical maximum readability — and that finding has held up for 150 years. Modern web designers who set body text to 110 characters per line are slowing their readers down by a measurable margin, and most of them don't know it.

The medium itself

People read 10–30% slower on screen than on paper, mostly because of subtle eye-strain effects. They read still slower on phones, where lines are short but the constant scroll fragments attention. Audiobook narration sits around 150–160 WPM — slower than reading because the audio version has no zooming or skipping ahead, so the average must accommodate slow listeners.

What "5 min read" actually means

If a 1,200-word article is labeled "5 min read," the publisher used a 240 WPM assumption. Treat the number as a rough order of magnitude:

• Under 3 min: a quick read; you'll finish in one sitting.
• 5–7 min: medium; this is the modal blog post; you might bookmark and return.
• 10+ min: long-form; you should set aside time, and probably half of "click" traffic will scroll halfway and leave (this is robustly observed in publisher analytics).
• 20+ min: you're in essay or short-fiction territory.

The standard word-count benchmarks

If you're writing rather than reading, here's the rough scale of common forms — what editors expect when they see a word count:

Some specifics that matter: a young-adult novel typically lands at 50,000–80,000 words; an adult literary novel at 80,000–110,000; a fantasy or sci-fi novel anywhere up to 150,000 (and the length is part of the genre expectation). The Great Gatsby is 47,000 words. The Lord of the Rings is around 480,000. Both are novels — the form is generous.

Three conventions worth knowing