Teleprompter speed in words per minute, and where 150 comes from
Many guides to teleprompter speed settle on 150 words per minute. It is a fair place to start, but nobody measured it on people reading from a prompter, and your own pace can sit well away from it. Below is where the number comes from, what the studies do measure, and how to set a prompter from your own voice.
Where 150 comes from
Articles on speaking rate, VirtualSpeech’s and Improve Podcast’s among them, credit the figure to the National Center for Voice and Speech, and one of them calls it a conversation rate. The source looks like a single sentence in an old voice-production tutorial on that centre’s site, which gives the average rate of speech for English speakers in the United States as “about 150 words per minute, by the way”. It cites no study, and the page is gone, though an archived copy is still readable. The figure may well be about right. It is not a measurement of anyone reading a script.
What the studies measure
Reading aloud has the best evidence. Marc Brysbaert’s 2019 review pooled 77 studies with 5,965 participants and puts the average adult reading aloud at 183 words per minute. The same review puts silent reading in English at 238 for non-fiction and 260 for fiction.
Talking is harder to pin down, because it depends on what you count as time. Jiahong Yuan, Mark Liberman and Christopher Cieri measured 2,438 recorded phone calls in a paper for Interspeech 2006. Across the whole call the rate was 196 words per minute. With the silences taken out it was 236. Added up turn by turn, it was 164. The same recordings give three answers, and all three are correct.
Audiobooks give a working figure. ACX, the marketplace where authors hire audiobook narrators, says most narrators record about 9,300 words per finished hour, which is 155 a minute with the pauses left in.
A rate is only as meaningful as the clock behind it. A prompter’s clock keeps running through every pause and every breath, so the figure you want is the one with the pauses in.
Why a prompter should run slower than you read
Your eyes are faster than your mouth: 238 words a minute read silently against 183 aloud, in that review. If you set a prompter by reading along in your head until it feels right, you tune it to your eyes, and the take turns into a chase. Set it by reading aloud.
Measure your own number
- Take about 300 words of the script you are going to record, not a sample text.
- Read it aloud the way you will on camera, pauses included, and time it.
- Divide the words by the minutes. 300 words in 2 minutes 10 seconds is 300 ÷ 2.17, about 138 words per minute.
- Start the prompter there and do one take. If you catch yourself waiting for the text, go up by 10. If you are chasing it, come down by 10.
Words and minutes
| Length | At 130 wpm | At 150 wpm | At 170 wpm |
|---|---|---|---|
| 1 minute | 130 words | 150 words | 170 words |
| 3 minutes | 390 words | 450 words | 510 words |
| 5 minutes | 650 words | 750 words | 850 words |
| 10 minutes | 1,300 words | 1,500 words | 1,700 words |
The table is only arithmetic. Use it with your own number to cut a script to length: a five-minute slot at 138 words per minute takes about 690 words.
Words per minute do not travel between languages
Christophe Coupé and colleagues compared 17 languages in a 2019 paper in Science Advances. Speech rate varied between speakers by a ratio of more than one to two, and the information each syllable carries ranged from 4.8 bits in Basque to 8.0 in Vietnamese. The two roughly cancel out, and every language landed near 39 bits of information a second. A language that sounds fast is not saying more per minute, so a words-per-minute figure from English tells you little about a script in Spanish or Japanese. Time yourself in the language you will record in.
When a fixed speed is the wrong tool
Any fixed speed is an average, and a take is not. You slow down for the line that matters and speed up through a list, and a scroll set in advance cannot know either. For a short script that is fine. For a longer or looser one, a prompter that moves with your voice takes the number out of it; the guide to using a teleprompter compares the four ways to control speed.
Speed in Wispim
Wispim, the iPhone teleprompter this site is about, has a Speed slider in two of its three modes, Sound and Constant, going up to 300. Most languages count words per minute, and Japanese and Chinese count characters per minute. On a fresh install, a new English script starts at 150. The third mode, Voice, has no speed setting: it follows the words you say, and its Lead setting decides how far the highlight runs ahead of your voice, from none to three words. How the following works explains the rest. At a computer, the online teleprompter on this site has a speed slider from 90 to 300 words per minute.
Questions
What is a good teleprompter speed for a beginner?
Your own, measured aloud with the method above. If you need a number before you have measured, start a little under 150 and adjust after one take. A prompter you have to wait for is easier to live with than one you are chasing.
How many words is a five-minute speech?
Five times your pace: 750 words at 150 words per minute, 650 at 130. Time yourself first and the table does the rest.
Why does my teleprompter feel too fast?
One common reason is that it was set by eye. Silent reading runs at about 238 words a minute against 183 aloud, so a speed that feels right while you read along silently is too fast to speak to. Time yourself aloud and set it from that.
Is 150 words per minute too slow?
For some people it is. The research average for reading aloud is 183. If 150 leaves you waiting for the text, raise it in steps of 10.
Is the speed the same in every language?
No. Syllable rates differ a lot between languages and the information per syllable differs the other way, so time yourself in the language of the script. Some prompters, Wispim among them, count Japanese and Chinese in characters per minute.