How reading time is calculated: the formula, the speeds and the limits

Reading time is the word count divided by an assumed reading speed. At 225 words per minute, a 1,800-word article is an 8-minute read. The arithmetic is trivial; the assumption is where all the uncertainty lives, because real reading speeds vary widely between people and between texts. The word counter uses 225 words per minute for reading and 150 for speaking, and this guide explains where figures like those come from and how far to trust them.

The formula

Reading time in minutes equals the number of words divided by words per minute (wpm). For 1,800 words at 225 wpm that is exactly 8 minutes; at 200 wpm it would be 9 minutes, and at 250 wpm about 7. Most sites round to the nearest whole minute or round up, and many show at least one minute however short the text. The word count is the easy part: words are counted as runs of characters separated by spaces, the way word processors do it, so well-known counts as one word.

How fast people actually read

Publishers and blogging platforms commonly assume somewhere between 200 and 250 wpm for adult silent reading, which is a reasonable middle. The most thorough review I know of, a 2019 meta-analysis by Marc Brysbaert covering 190 studies and more than 18,000 participants, estimated average adult silent reading in English at about 238 wpm for non-fiction and 260 wpm for fiction. Most adults fell between about 175 and 300 wpm for non-fiction. Reading aloud averaged about 183 wpm.

The same paper found that rates are lower for children, older adults and people reading in a second language, and that higher figures often quoted in popular writing are overestimates. Claims of reading many hundreds of words a minute with full understanding should be treated with suspicion.

Speaking time

Speech is slower than silent reading. Audiobooks are commonly recommended at around 150 to 160 wpm, a pace people find comfortable to hear, while slide presentations tend to run slower, nearer 100 to 125 wpm, because of pauses and slide changes. That is why 150 wpm is a common planning figure for a steadily delivered talk: a five-minute speech is about 750 words, a ten-minute one about 1,500. If you will be presenting slides, taking questions or speaking to a large room, plan for fewer words. Reading your script aloud once against a timer is more reliable than any estimate.

Why estimates are off

• Difficulty. Dense technical or academic writing is read more slowly than a light feature, and readers go back over hard passages. The readability checker gives a sense of how demanding a text is.
• Skimming. Many people scan web articles rather than read every word, so they finish a 10-minute read in three.
• Non-text content. Images, charts, tables and code take time to study but add few words, and a plain word count ignores them.
• Language and script. Languages differ in how many words they need to say the same thing, and Chinese, Japanese and Thai do not separate words with spaces, so per-word speeds do not transfer between languages.
• The reader. Speed varies with age, fluency, tiredness and interest.

Treat a reading time as a rough size label, like small, medium or large, rather than a promise.

Showing reading time on your writing

If you add reading times to a blog or newsletter, pick one speed and use it everywhere, so readers can compare pieces fairly. Count only the main text, not navigation, comments or footers; round to whole minutes; and consider labelling pieces heavy with images or code as longer reads. If you need to trim a piece to fit a time slot or a reading-time target, the word count is the lever: the filler word remover cuts the easiest words first. For print, the words to pages calculator converts the same count to pages, and How long is an essay? Typical word counts, pages and paragraphs covers typical lengths for assignments.

How the word counter estimates it

The word counter counts words as text separated by spaces, like Word and Google Docs, and uses the browser's built-in word segmenter for Chinese, Japanese and Thai. It divides the total by 225 for reading time and by 150 for speaking time, showing seconds for anything under a minute and minutes and seconds above that. The reading figure sits just below the research average for non-fiction, so its estimates lean slightly long rather than short. If you want to practise reading at a set pace, the speed reader shows text one word at a time at the wpm you choose. Flesch reading ease and grade level, explained honestly covers the readability side of how long a text feels.