If you give presentations and you use PowerPoint, have you heard of the 10/20/30 rule? Presentation gurus such as Garr Reynolds and Guy Kawasaki swear by it, and this is how they describe it.
Basically, it's this:
It’s quite simple: a PowerPoint presentation should have ten slides, last no more than twenty minutes, and contain no font smaller than thirty points.
Ten slides. Ten is the optimal number of slides in a PowerPoint presentation because a normal human being cannot comprehend more than ten concepts in a meeting — if you must use more than ten slides to explain your point, you probably don’t have a point!
Twenty minutes. You should give your ten slides in twenty minutes. Yes, you have an hour time slot, but you’re using a Windows laptop, so it will take forty minutes to make it work with the projector. Even if everything goes perfectly, people will arrive late and have to leave early. In a perfect world, you give your pitch in twenty minutes, and you have forty minutes left for discussion.
Thirty-point font. The majority of the presentations have text in something like a ten point font. As much text as possible is jammed into the slide, and then the presenter reads it. However, as soon as the audience figures out that you’re reading the text, they read ahead of you because they can read faster than you can speak. The result is that you and the audience are out of step.
The reason people use a small font is twofold: first, that they don’t know their material well enough, and this is their script; second, they think that more text is more convincing.
Force yourself to use no font smaller than thirty points. It will make your presentations better because it requires you to find the most salient points and to know how to explain them well. If “thirty points,” is too dogmatic, then try this: find out the age of the oldest person in your audience and divide it by two. That’s your optimal font size.
10/20/30