Why a speech is slower than reading the same page aloud
Reading a passage aloud to yourself averages about 183 words per minute across the studies pooled in Brysbaert's 2019 meta-analysis. Delivering the same passage to an audience is slower, and the difference is not nervousness — it is structure. You pause after a claim so it lands. You stop while people look at a slide. You repeat a definition. You leave a beat before a transition so the audience knows a new section has started. None of those seconds contain words, and all of them belong to the talk.
Speech and debate coaches, conference organisers and broadcast producers converge on a working range of roughly 120 to 160 words per minute for prepared delivery, with technical material at the lower end and light narrative at the upper. The default here is 130, which suits a presentation with slides and content the audience has to think about. If you speak fast naturally, use 150. If you are presenting equations, an unfamiliar framework, or speaking to an audience in their second language, drop to 110.
The important discipline is to measure rather than guess. Record yourself delivering two minutes of the actual script at the pace you intend to use, count the words, and divide. Most people discover they are 15 to 25 words per minute away from their assumption, which on a twenty-minute talk is the difference between finishing comfortably and being cut off mid-conclusion.
Where the minutes actually go
A talk is not only spoken words, and the calculator makes the non-speaking time explicit because that is where overruns come from. Three overheads matter.
Slide transitions. Each new slide buys the audience a few seconds of reading during which you should be quiet. Three seconds is the minimum for a single image; five to eight is realistic for a slide with a chart or several bullets. Ten slides at five seconds is 50 seconds — nearly a fifth of a five-minute talk, and almost always unbudgeted.
Questions. If your slot includes questions, those minutes are not available for the script. A 20-minute conference slot with five minutes of questions gives you 15 minutes of speaking, so budgeting words against 20 minutes overruns by a third.
Everything else. Walking to the lectern, waiting for the projector, an introduction by a chair, a demo that has to load, laughter after a joke that works. A minute of unallocated slack in a twenty-minute talk is prudent, not pessimistic.
The calculator subtracts pauses and question time from the slot before multiplying by your rate, which is why the word budget it returns is smaller than a naive rate × slot product. Working the other way, it adds those overheads onto the speaking time to give the total you will actually occupy. Both directions use the same three quantities, so they always agree.
Words per slide is the last output and the most diagnostic. Divide it by your rate and you get the minutes you will spend on each slide. Anything much above two minutes per slide means the deck is not carrying the talk, and anything below about twenty seconds means you are flicking through faster than an audience can follow.
Worked example: a 900-word script in a 7-minute slot
You have written 900 words for a seven-minute slot. You have twelve slides, you allow five seconds of silence at each transition, and the chair has asked for two minutes of questions inside the slot. You have timed yourself at 135 words per minute.
- Pause allowance. 12 slides × 5 seconds = 60 seconds = 1.00 minute.
- Time left for the script. 7 − 1.00 − 2 = 4.00 minutes.
- Word budget. 4.00 × 135 = 540 words.
- Speaking time for what you actually wrote. 900 ÷ 135 = 6.67 minutes.
- Total on stage. 6.67 + 1.00 + 2 = 9.67 minutes.
- Overrun. 9.67 − 7 = 2.67 minutes over. At 135 words per minute that is 2.67 × 135 = 360 words to cut, taking the script from 900 to the 540-word budget.
- Sanity-check the deck. 540 words over 12 slides is 45 words per slide, or 45 ÷ 135 = 20 seconds of speech per slide. That is tight; six slides at 90 words each would give a more comfortable 40 seconds.
The lesson generalises. Cutting a talk by a third feels brutal until you notice that the pause and question overheads alone consumed 43% of the slot. Most overruns are not caused by writing too much prose; they are caused by budgeting words against the full slot as though nothing else happened in it.
How to use the numbers when you rehearse
Treat the calculated time as the floor. Live delivery almost always runs longer than rehearsal, because audiences generate friction: a question mid-talk, a laugh, a microphone that fails, your own instinct to elaborate on the point that is landing. Planning to finish at 90% of the slot leaves room for that and gives you the option to stop early, which no chair has ever objected to.
Rehearse against the word budget, not against a stopwatch alone. A stopwatch tells you that you overran; the budget tells you how much to cut and where. Multiply the overrun in minutes by your rate to get words, then remove that many words from whichever section you can defend least. A 90-second overrun at 130 words per minute is 195 words — usually one anecdote or two paragraphs of background.
Watch for the trap in the reverse direction. When the calculator says a five-minute talk holds 650 words, that is 650 words of finished, spoken prose. Bullet points on a slide are not spoken words, and a script with stage directions and slide cues has a word count larger than the words you will say. Count only the sentences that will come out of your mouth.
Finally, remember that rate is not a virtue. Speeding up to fit more content in is the most common and least effective response to an overrun, because comprehension falls as delivery rate rises, most sharply on unfamiliar or technical material. Cutting content is almost always the better trade. If you want to see how the same word count behaves as private reading rather than speech, the reading time calculator uses silent rates, which run roughly twice as fast as delivery.
Word counts for common speech lengths
| Speaking time | At 110 wpm (technical) | At 130 wpm (presentation) | At 150 wpm (brisk) |
|---|---|---|---|
| 1 minute | 110 | 130 | 150 |
| 2 minutes | 220 | 260 | 300 |
| 3 minutes | 330 | 390 | 450 |
| 5 minutes | 550 | 650 | 750 |
| 7 minutes | 770 | 910 | 1,050 |
| 10 minutes | 1,100 | 1,300 | 1,500 |
| 15 minutes | 1,650 | 1,950 | 2,250 |
| 20 minutes | 2,200 | 2,600 | 3,000 |
| 30 minutes | 3,300 | 3,900 | 4,500 |
| 45 minutes | 4,950 | 5,850 | 6,750 |
| 60 minutes | 6,600 | 7,800 | 9,000 |
Every cell is minutes × rate. A one-hour keynote at presentation pace is about 7,800 words — roughly the length of a journal article, which is why full scripts for long talks are rare.
What makes a talk overrun
- Budgeting words against the whole slot. Slide pauses and questions are minutes you cannot fill with script. A 20-minute slot with 5 minutes of questions and 20 slide changes has about 13.5 minutes of speaking time in it.
- Using your reading rate instead of your delivery rate. Reading aloud averages about 183 words per minute; presenting is typically 120 to 160. Timing a script by reading it at your desk understates the live length by a quarter or more.
- Counting slide text as script. Only words you will actually say belong in the word count. Bullet points, titles and speaker notes you plan to skip do not.
- Ignoring the demo. Anything that has to load, connect or be typed live takes two to three times as long on stage as it does in rehearsal, and it is silent time.
- Speeding up to fit. Raising the rate is the standard response to an overrun and the worst one; comprehension drops fastest on exactly the technical content you were trying to preserve. Cut instead.
- Leaving no slack. An unallocated minute in a twenty-minute talk absorbs the microphone that fails and the question asked mid-flow. Planning to finish at 90% of the slot is a working professional habit.
Related timing and drafting tools
Speaking rate and reading rate are different quantities and mixing them is the most common error in talk planning. Silent reading of non-fiction averages about 238 words per minute, so a script that takes seven minutes to deliver takes under four to read — which is why handing out the script is never equivalent to giving the talk. The reading time calculator handles the silent side, and if you want your own oral rate rather than an average, measure it with the reading speed calculator, which separates raw rate from accuracy.
When the assignment is specified in pages rather than minutes — common in classroom speech units, where a teacher asks for a three-page speech — convert the pages to words first with the words to pages calculator, since a double-spaced page carries about half the words of a single-spaced one and the difference doubles the talk. And if you are writing for an audience rather than a reader, check the script's difficulty with the Flesch Reading Ease calculator: spoken prose that scores below about 50 is hard to follow by ear even when it reads well on the page, because a listener cannot go back.
One structural note that no calculator can give you. Word budgets constrain a talk, they do not shape it. A five-minute talk with 650 words has room for one idea developed properly, or three ideas asserted and none demonstrated. The arithmetic tells you which of those you have written.