The question almost always arrives the same way: how long should the video be? The honest answer is that there is no single number. There is the time the idea needs and the time the format allows. A 30-second video that says nothing is long; a 10-minute one that holds attention is short.
What defines the length
Length is a consequence of three things: the promise (what the viewer came for), the format (where they will watch it) and the cost (how much production time fits the project). When someone sets the duration before defining the content, the video is born at the wrong size: either there is room to fill, or there is not enough time to conclude.
The rule I use: write the script first, time the read, and only then decide the final length. Duration is the result, not the goal.
Ranges by format
These are the ranges I use in practice, based on what works in each context. They are not laws, they are starting points:
| Format | Usual range | What tends to work |
|---|---|---|
| Reels, TikTok, Shorts | 15 to 60 s | 20 to 40 s for a single idea; the first 2 s decide the rest |
| Stories | 5 to 15 s per screen | one message per screen, in a sequence of 3 to 5 screens |
| Ad (paid media) | 15 to 30 s | one promise, one proof, one action |
| Corporate/institutional video | 60 to 120 s | who you are, what you do and why to trust you |
| Explainer video | 90 to 180 s | a problem, the solution and how it works |
| YouTube (search and education) | 6 to 12 min | density and chapters; it can be long if every minute pays |
| Lesson or course | 5 to 15 min | one concept per video, with a pause for practice |
Notice that the range changes with the context, not with the subject. The same theme can become a 30-second Reel or a 10-minute lesson; what changes is the depth of the promise.
How to calculate runtime before shooting
The math is simple and answers most doubts: words per minute. Spoken video sits comfortably between 130 and 150 words per minute. Above that, comprehension drops; below it, the pace drags. With 1,000 words you have about 7 minutes of narration; with 300, about 2 minutes.
Then come the breaths: pauses, demonstrations, stretches without speech, B-roll. In practice, I add 10% to 20% to the reading time. If the video has music and product scenes, add more.
Two tools on the site help at this stage: the video length calculator turns words into minutes at the pace you choose, and the post on speaking rate shows how many words fit in a minute and why the range shifts with the audience.
The mistake of padding the video
The most common mistake is not getting the length wrong, it is padding to reach the length. When the script has 40 seconds of content and the person wants 2 minutes, the result is repetition, a long introduction and a farewell. The viewer feels it.
The test I use: if I cut the first 10 seconds, does the video still make sense? If yes, the opening is spare. Another: if I remove half the words, does the message survive? If it survives, the video is longer than it needs to be.
A short video is not a shallow video. Short is what has no fat.
When a long video is worth it
A long video works when the viewer chose to learn, not when they were interrupted. On YouTube, in courses and in search content, the person came for the topic and stays for the depth. In those cases the length can be 6, 10, 15 minutes, as long as every minute delivers something.
What does not work is the long video in a context of passage: feed, ad, email. There, time is contested and the length must be the shortest possible to deliver the promise.
Practical summary
- Write the script before defining the duration.
- Count the words and divide by 140 (comfortable speech).
- Add 10% to 20% for pauses and scenes without speech.
- Use the format range as a starting point, not a rule.
- Cut whatever does not pay for the time it takes.
Frequently asked questions
What is the ideal length for a Reel?
Between 20 and 40 seconds for a single idea, and up to 60 seconds when there is a short sequence (before and after, step by step). The first 2 seconds define whether the person stays.
How long should a corporate video be?
Between 60 and 120 seconds. Enough to say who you are, what you do and why to trust you. Beyond that, only if there is a real story to sustain it.
How many words fit in 5 minutes of video?
At 140 words per minute, 5 minutes take about 700 words of narration, plus 10% to 20% for pauses. The video length calculator does the math at the pace you choose.
Do long videos lose audience?
It depends on the context. In feeds and ads, yes. In search, courses and YouTube, no: people who chose to learn stay if the content sustains it. The problem is not the length, it is the time without delivery.
Is runtime the same as speaking rate?
No. Speaking rate is the speed of the voice-over, in words per minute. Runtime is the final length of the video, which includes speech, pauses and scenes without narration.
Does a 2-minute video work on any social network?
No. Each platform has its own context and limit. The format guide shows the sizes and durations per platform.
References
- Own experience — producing corporate, explainer and animation videos for companies (2005-2026).
- Video length calculator.
- Speaking rate in video.
If you want to define the length with the script in hand, get in touch.
— Ricardo A. B. Graça · ricolandia.com