neo@web:~ $ cat guides/reading-time-calculator.txt
Silent reading time is words divided by 238 wpm, the average adult silent reading rate. Reading aloud takes words divided by about 150 wpm. A 1,200-word article is 5 minutes of silent reading but 8 minutes read aloud. The gap exists because your eyes move faster than your mouth.
"Reading time" means two different things, and mixing them up is the most common timing mistake in publishing. Silent reading time is how long it takes a reader to read your text quietly: words / 238 wpm, the average adult silent reading rate. Reading-aloud time is how long it takes to speak the same text: words / 150 wpm, the standard speaking pace.
The same 1,200-word article is 1,200 / 238 = 5.0 minutes of silent reading, but 1,200 / 150 = 8.0 minutes read aloud. That 3-minute gap is the whole game: blog "5 min read" labels use the silent number, while podcast scripts, video narration, and speeches must use the aloud number.
Silent reading minutes = word count / 238. The 238 wpm figure comes from reading research averaging across adult readers and ordinary prose. It shifts with difficulty: dense technical writing reads closer to 150 to 200 wpm, light fiction closer to 300. But 238 is the standard default, and it is the number behind the reading-time labels you see everywhere.
Worked examples, all at 238 wpm:
Reading-aloud minutes = word count / 150. Use this for anything that will be spoken: video scripts, podcast narration, speeches, audiobook estimates, and teleprompter timing. Your mouth cannot sustain 238 wpm and stay intelligible; trained audiobook narrators top out around 150 to 160 wpm, and that is with professional breath control.
Same texts, read aloud at 150 wpm:
The practical rule: multiply silent reading time by 1.6 to estimate reading-aloud time (238 / 150 = 1.59). If the label says 5 minutes, the voiceover is 8.
Blog platforms show reading time to help readers decide whether to start. Medium, Substack, and most news sites compute words / 238 (or a nearby rate) and round. The label answers "how long will this take me to read," and since readers read silently, the silent number is correct. It is only wrong when a writer copies the label into a video script plan, where the aloud number applies. A "10 min read" essay is a 16 minute narration: 2,500 words at 150 wpm is 16.7 minutes.
Video narration runs slightly slower than live speaking because of pauses, emphasis, and retakes. A good planning number is an effective pace 10 percent slower than your speaking pace: at 150 wpm speaking, plan video at about 135 wpm. That turns the 2,000-word script from 13.3 minutes into 2,000 / 135 = 14.8 minutes, about 14 minutes 50 seconds. The speech time calculator builds this in: its teleprompter estimate automatically assumes the 10 percent slowdown.
The 238 average hides real variation. College-educated adults reading familiar material often hit 280 to 300 wpm; readers working in a second language or through dense jargon may read at 150 to 200. Screen reading runs about 10 to 20 percent slower than print for most people. None of this changes the planning math much: for publishing labels, the standard 238 keeps you comparable with every other site; for your own scheduling, time yourself on one article (words / your minutes) and use your number.
Silent or spoken, get both numbers. The calculator shows speaking time, silent reading time, and the teleprompter estimate side by side, so a script and an article never get mixed up again.
Open the free speech time calculator and paste your script to get your exact time at every pace.
Divide the word count by the reading rate. For silent reading, use 238 wpm: a 1,200-word article is 1,200 / 238 = 5 minutes. For reading aloud, use 150 wpm: the same article is 1,200 / 150 = 8 minutes.
About 238 wpm for silent reading by an average adult, and about 150 wpm for reading aloud. Dense or technical text reads slower (150 to 200 wpm silent); light fiction reads faster (up to 300 wpm).
About 4 minutes 12 seconds silently (1,000 / 238 = 4.2 minutes) and about 6 minutes 40 seconds aloud (1,000 / 150 = 6.7 minutes).
Your eyes can move across text at 238 wpm or more, but speech is limited by articulation, breathing, and the need to be understood. Even trained narrators top out around 150 to 160 wpm aloud.
It means about 5 minutes of silent reading, roughly 1,200 words at 238 wpm. If you turned that post into a narrated video, it would run about 8 minutes at speaking pace.
$ ls guides/
how-many-words-5-minute-speech -- How many words for a 5 minute speech? 750 words at 150 wpm, with the trim and expand playbooks.
words-per-minute-calculator -- Words per minute calculator: measure your own speaking pace in two minutes.
how-many-words-3-minute-speech -- How many words is a 3 minute speech? 450 words at 150 wpm, with the pace table.
how-many-words-10-minute-speech -- How many words is a 10 minute speech? 1,500 words, plus how to structure a longer talk.
neo@web:~ cd ~/speech-time-calculator (back to the calculator)