When you create a presentation and you use slides, it is likely that you use some text in your slides (not too much, don’t forget!). In those cases, make sure your text is big. In fact, very big.
Too often I see slides with text that uses 12 point fonts. But no one can read 12 point fonts, especially those who are sitting at the back of a room. The fact that you can read your slides from your laptop doesn’t mean that those who are sitting in the room can also read them. Therefore, the rule is simple: never use 12 point fonts.
The question then is, what’s the right size? There's no one-size-fits-all approach, it always depends on the context. However, to give you a guideline, Guy Kawasaki gave us a useful hint in his famous 10-20-30 rule: 10 slides, 20 minutes, 30 points as minimum font size.
30 points, not 12. The power of this rule is that it pushes you to include as little text as possible in your slides. A small amount of large text allows your audience to read your slides and at the same time you avoid cluttering your slides with unnecessary details.
Here’s is a small secret I’ve learned from Nancy Duarte: if you want to know whether your audience will be able to read your slides, open Power Point, select Slide Sorter from the View menu (Light table in Keynote) and zoom out at 66%. If you can still read the text, your audience will too.
If you want to learn more about how to make better presentations, download my report Top 7 Mistakes People Make When Creating Business Presentations.