Every time you have to give a speech or make a presentation, do this calculation

Here’s a practice to develop with regard to your public speaking. It’s something that I started doing many years ago. It’s a simple calculation that should take 30 seconds (or less if you use a calculator) but the result is always powerful and sobering.

Here’s what you do: Take the number of people whom you anticipate will be in the audience and multiply that number by the amount of time you have to speak. So, for example, if you are asked to make a 30-minute presentation to 20 members of your department, the calculation would look like this:

30 minutes x 20 people = 600 minutes = 10 hours

Many speakers think about time only in terms of the length of their speech or presentation.  But in the example above, your 30-minute presentation is not just 30 minutes. It is 30 minutes for the first person in the audience plus 30 minutes for the second person plus 30 minutes for the third person, etc.

CalculatorThe total amount of time would be 10 hours for one person. How valuable is 10 hours of someone’s time? That’s a little more than one working day for most people. If you were given 10 hours of someone’s time, you would want to make that time as productive as possible. You should look at the time your audience is spending with you in the same way. The bigger your audience and / or the more time you have to speak, the greater the amount of time involved.

Last month, I was invited to Munich, Germany to give a one-hour talk to approximately 150 managers at Danone, one of the world’s leading food companies. As always, I did the calculation:

1 hour x 150 people = 150 hours

Now, a standard work week is 40 hours. Yes, I know that there are many businesses where the work week is longer—I worked for many years as a lawyer in one of Canada’s leading law firms so I know very well what a long work week is—but I stick with 40 hours.

So, for my speech, it was like I had been given almost an entire month of work time for one person. That’s an incredibly valuable commodity, especially in today’s world where there are so many people and things competing for our most important non-renewable resource. I want to treat that time with as much respect as I can and give as much value as I can for it.

That’s why you should do this calculation. It is a quick and effective way to put things in perspective and remind yourself of the opportunity you have been given. And keep in mind that I have limited my calculation to the length of the speech or presentation. In reality, you have to add the time it takes people to get to the speaking venue, the time it takes them to return to work or home, the time spent getting back up to speed on projects or responding to accumulated emails, etc. So the true number is even bigger.

Do this calculation every time you give a speech or make a presentation. It will change, in a good way, how you think about your speaking engagements.


About John Zimmer

International speaker, presentation skills expert, lawyer, improv performer
This entry was posted in Motivation, Preparation and tagged , , , . Bookmark the permalink.

17 Responses to Every time you have to give a speech or make a presentation, do this calculation

  1. Pingback: Zen and the Art of Public Speaking | Manner of Speaking

  2. Christina Kwok says:

    hi john,
    interesting thought. Another way to look at it is that if 10 corporate people attended your 30-min presentation, then 300 mins of corporate downtime happened. Company needs to know it was worthwhile and speaker should keep that in mind.

  3. Pingback: Breathing Easy | Manner of Speaking

  4. Julie Zimmer says:

    This also applies to teachers and their classes. I will keep this in mind. Thanks for spreading the word!

  5. Great post John.

  6. Sandra Lizioli says:

    Great formula for preparation. What do you say about 1 hour prep for 1′? 30 mins = 30 hours.

    • John Zimmer says:

      Thanks for the comment, Sandra.

      Regarding your question, I believe you are asking whether the formula of 1 hour of preparation for every 1 minute of speaking time is sound. I have given speeches where I prepared much more than 1 hour per minute of speaking time and I have had speeches where I prepared less. A lot depends on well the speaker knows the material, whether he has given part or all of the speech before, etc. To the extent that the 1 hour : 1 minute ratio holds, I would include research and reflecting on the speech as part of the hour in addition to preparing and rehearsal.

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  8. Rashid says:

    Dear John:
    Thanks again, for bringing this necessary and too frequently ignored thought process to attention.
    I have been doing something similar for long time too. Not only when I am speaking, but also when I am in an audience–specially in company Town Halls (or similar).
    I prefer to use the term “person-hours” instead of just “hours” and then multiply it by the average person-hour-salary to compute the cost of participation / investment in the event. You can chose to use a higher $ figure by using billing rate instead of salary. This is the value threshold that has to be crossed, failing which there was an inadequate ROI.
    Most corporate Town Hall meetings do not deliver an acceptable ROI.
    This is a strong argument that can be made for investing top quality presentation coaching.
    Check out this Gil Amelio example https://www.youtube.com/watch?v=PsBVyUDs-84
    The uncomfortable truth is that most town hall talks are far more similar to the Gil Amelio’s effort than we care to admit. It is simultaneously a travesty and an opportunity.
    Keep up your good work … Good Luck … Best Regards … Rashid

    • John Zimmer says:

      Thank you, Rashid, for the comment. I just watched Mickeleh’s video. Very interesting back story from someone who was involved in one Apple’s biggest MacWorld events. Thanks for sharing it.

  9. Very sobering numbers, indeed! It’s great that you’re spreading the word about this.

    As you say, it concerns our most important non-renewable resource. That was my opening in this post about presenting online, too.

    (The vast majority of webinars start with at least 5 minutes of time-wasting. Multiply that by the headcount and you get a shocking result, before the useful content has even started – if it ever does!!)

    • John Zimmer says:

      Thanks, Craig. And thanks for sharing your post. Webinars are tricky animals because now you are adding multiple locations, multiple levels of quality in terms of equipment and connectivity and multiple levels of sophistication when it comes to technology. Sending out simple, clear instructions by email to all participants beforehand is one way to avoid some of the delay, but I have yet to see a webinar run completely hitch free. Even the best ones hit some bumps. Cheers!

  10. Friederike says:

    Dear John, I always use this calculation when I talk about “Beeing on Time”. Multiply the number of people kept waiting with the number of minutes the meeting started late time by 50 (hourly wage – very low calculation) and devide by 60. That is how much money was wasted. It actually does make a difference if one looks at time in proportion to number of people involved.

    • John Zimmer says:

      Thanks for the comment and calculation, Friederike. I know exactly what you are talking about. When I worked in the UN system, I did something similar as so many meetings started late and then meandered past the scheduled finish time with little, if anything, accomplished. It gets depressing if you do it too often! That’s the good thing about the calculation in the post: it is forward-looking, proactive and inspiring. Cheers!

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