People often ask me, “What is the right number of slides for a 20-minute (or 30-minute, or 40-minute, etc.) presentation.” I always respond the same way: “I don’t know. Three, 20, 50, 17, none?”
There is no right answer. It depends on a number of variables, including the audience, the subject and the context. However, the number of slides in your presentation is less important than the way in which they are designed and used. I would rather watch a presentation with 50 well designed slides than one with 15 poorly designed slides.
Of course, you cannot disregard the time element. If you have 10 minutes and 200 slides, you’ll succeed in giving your audience a headache and not much else. You should use as many (well designed) slides as are necessary to enhance and support your message. No more, no less.
In 2010, I wrote a post on the same idea after reading an article by Seth Godin. I was prompted to revisit the issue after recently coming across a wonderful slide presentation on BBC News Magazine that is narrated by John Hockenberry, an American journalist and commentator who has been in a wheelchair since a car accident left him paralyzed.
In this presentation, Hockenberry shares the real message that people around the world should take away from the 2012 Paralympics that were held in London. The presentation lasts only three minutes but has, by my count, 45 slides. That’s one slide every four seconds. Yet not one of them was superfluous or out of place.
Many people mistakenly believe that having more slides is inherently bad. So they end up cramming too much information on fewer slides. You are much better off spreading the information across more slides. That way, you give each idea its own space and it is easier for the audience to digest. And you will probably be able to cover the material in less time.