What Do I Do if My Presentation is Running Short or Long?
Running short is usually not a problem. Sure, if you have been paid $50, 000 to give a keynote speech in front of 5, 000 people and you are supposed to speak for an hour and are done after 10 minutes, then you have a problem on your hands. But I'm assuming—since you simply want to give a pretty good presentation—that you aren't in the professional speaking business. Great! That takes all the pressure off.
It's highly unlikely that, if you've been allotted 30 minutes and finish after 20, anyone in your audience is going to be upset with you; in fact, you are likely to be proclaimed a hero! If you have covered your main points and done so in a memorable way, then sit down. Don't worry about running a little short.
However, sometimes people run short because they race through their speech in order to finish faster and sit down. This is a problem. Occasionally, people finish earlier than their allotted time because they strip the speech of all interesting examples, stories, case studies, and vignettes. This, too, is a problem.
Your goal should not be to give a presentation in as brief amount a time as possible or to finish in less than the time allotted. Instead, you want to communicate a few important ideas that you care about and that you want the audience to care about. If you do that, the time will often take care of itself.
If you are allotted 30 minutes to speak and you finish after ...