How reading time is calculated (and why every blog uses a different number)

You've seen the labels: "3 min read", "8 min read", "12 min read". They look authoritative. They're not. The formula is two lines of arithmetic, and the magic number behind it varies by a factor of three across the web. Here's what's actually going on.

The formula

Every reading-time estimator computes the same thing:

minutes = word_count / words_per_minute

That's the whole formula. The only thing publications disagree on is what to use for words_per_minute. And the disagreement is wild.

What different platforms use

• Medium: 265 WPM (English), with extra time added for images.
• WordPress reading-time plugins: typically 200 WPM.
• Substack: 200 WPM.
• Ghost: 275 WPM.
• News sites: 200–250 WPM.
• Academic readability research: 250 WPM for adults, but with huge variance.

Same 1,000-word article: Medium says "4 min read", WordPress says "5 min read", Substack agrees, Ghost says "4 min read". The labels are consistent within a platform but not across.

What the research actually says

Reading speed depends on:

• Material complexity. Plain narrative: 250–300 WPM. Technical material: 150–200 WPM. Academic papers with formulas: 100 WPM or less.
• Reader purpose. Casual scanning: 400+ WPM. Reading for retention: 200–250 WPM. Reading for comprehension and test: 150 WPM.
• Reader age and education. 20-somethings read faster than 60-somethings; advanced degrees correlate with faster reading.
• Language. CJK languages have different "word" boundaries; counting words doesn't translate directly. Spanish and Italian read slightly slower than English per word; German is faster.
• Time of day, fatigue, distractions. Real reading happens in the wild, not in lab conditions.

Brian Cronin and Sven Birkerts have both noted that web reading averages closer to 180–230 WPM when you account for distractions, scanning, and re-reading. The 265 WPM number Medium uses is closer to silent reading in a quiet room.

What about speaking time?

For podcasts, audiobooks, and presentation scripts, speed is dramatically lower:

• Conversational speech: ~130 WPM.
• Audiobook narration: 150–160 WPM.
• News broadcast: 150–170 WPM.
• Auctioneers: 250+ WPM (rare).

If you're sizing a presentation, use 130 WPM. A 1,000-word script will take you about 7.5 minutes to deliver — much longer than the 4 minutes a reader would spend silently.

What about images and code?

Medium adds 12 seconds for the first image and 11 seconds for each subsequent one. That's a reasonable heuristic for engagement, though academic research on image attention is messy.

Code blocks are different. Programmers read code at maybe 50 WPM if they're actually parsing it. A 20-line code block in a tutorial isn't a 5-second pause; it's closer to a 30–60 second engagement. Most reading-time estimators ignore this and undercount technical articles.

What you should do

If you're a blog publisher

Pick a WPM and stick with it. Consistency within your site matters more than absolute accuracy. Most thoughtful publishers use 225–250 WPM for general audiences and 175–200 WPM for technical content.

If your audience includes a lot of non-native English readers, drop another 25 WPM. They read slightly slower and notice the difference.

If you're a reader

The labels are estimates, not promises. A "5 min read" on a technical topic might take you 12 minutes if you stop to think. A "12 min read" of breezy prose might take you 7. Use them as a rough order-of-magnitude guide, not a precise commitment.

If you're sizing a presentation

Don't use reading time. Use speaking time. Aim for 130 WPM and add 20% for pauses, audience questions, and the inevitable tangents. A 10-minute slot is about 1,000 words of script, not 2,500.

Our calculator

Our reading time estimator gives you three numbers: slow (150 WPM), average (200 WPM), and fast (250 WPM), plus a separate speaking-time estimate at 130 WPM. The slider lets you set custom speeds for specific audiences.

The point isn't to give you "the right number" — there isn't one. It's to give you a defensible range so you can pick the WPM that matches your audience and stop pretending the label is more precise than it is.