Determine the Length of Your Presentation
1/ Tighten your talk and rehearse your timing
Based on the amount of time you have been given to present, calculate 60% of the total (ex. 40 minutes for an hour-long presentation). This is the amount of time you should plan on using for the delivery of your actual talk. Then, add a brief summary/rousing conclusion (3 minutes) after your Q&A.
2/ Plan two natural endings
Plan out two endings of different lengths. In case your presentation is running long you will have a natural place to end a bit early.
3/ Practice with the clock counting up
Time each of your practice sessions, and record the total time and how long you are over by at the right. Practice until you hit your goal time.
4/ Practice with the clock counting down
Divide your content into quarters, calculate a time stamp for the end of each quarter. Then, make a note the slide number that you should be at for each time stamp.