You might think you can reuse slides for a presentation you gave to a smaller group of people for your next keynote speech, but you’d be wrong!
Several clients recently were surprised when I asked how they’d changed their slides to accommodate presenting to a large audience in a significant physical space.
How does the size of an audience affect a presentation?
Here are five tips to help you design slides that work for a large audience.
Tip #1 – Slide size
In the past, there was only one slide size. The “Standard” slide size is used overhead projectors. The default in PowerPoint is now “Widescreen”. If you open a new file, it will automatically be widescreen. What’s the difference? The standard slide size is square, whereas the widescreen slide is broader. Why does this matter? If we’re presenting on the widescreen monitor and with standard slides, we’re not utilising the full view for our audience. What happens is that the audience will see two black bars down the left and right sides of the screen. The reverse of this is true; if we present widescreen slides on an overhead projector, our audience will see two black bars along the top and bottom of the screen. Let’s imagine you’re sitting at the back of a large venue listening to your favourite speaker and looking at their accompanying slides. The screen you’re looking at is far away. A third of the screen is black! Now that is a waste of valuable slide space.
It makes sense that the screen is fully utilised so that every audience member gets the opportunity to see the information you have on the slide. I advise contacting the venue and asking them what type of screen they’re using. If it’s a modern conference facility, it will probably be widescreen. If it’s a hotel, it may be an overhead projector.
You may need to reformat the slides if you’re adapting an existing slide deck and changing the slide size. If you’re starting from scratch, ensure you have the right slide size before you start; otherwise, you’ll have additional work to do to reformat the slides!
Tip #2 – Size of text
I attended a presentation earlier this year. I was sitting in the middle of the room. The presenter knew their content well but backed it up with very text-heavy slides. The problem was that I couldn’t see the text on the slides. Imagine what it was like for the people sitting at the back. They didn’t stand a chance! When presenting to a large audience, we need to allow for the fact that people at the back of the room cannot read lots of text on our slides, so we need to keep text to a minimum and ensure it is large enough to read. It will be better to have one or two words to capture the concept on a slide than a sentence.
Tip #3 – Concepts
A picture tells 1000 words, so pictures are perfect when presenting to a large audience. I worked on a slide deck for a TEDx Presentation recently. The concept we were trying to get across was “one in six children”. Rather than writing the words “one in six children”, I used an infographic of six children on a slide. The children were white on a black background. I duplicated the slide and changed one of the children from white to red. It is a much more powerful way to represent 15%.

Tip #4 – Photos
The best way to use images for a large audience is to have one photo per slide and ensure the photo fills the total slide size. If you’re a Microsoft 365 subscriber, there is a fantastic bank of high-quality images at your disposal. You’ll find these on the insert tab under Pictures and Stock Images. These are free to use in your PowerPoint slides, and as they are high quality, they will look good on screen. Microsoft launched stock images in 2021 with 8000 photos, adding new pictures regularly. If your images are poor quality, they will look pixelated on screen. Always make sure you have high-quality images. Some low-cost image banks offer PowerPoint add-ins. One of these is a subscription service called Pickit, which provides unlimited access to over a million licensed images, icons, illustrations, and royalty-free photos.
Tip #5 – The last slide
I often see slides that finish with “thanks” or “any questions”. I ask you, is this memorable for your audience? Of course, it isn’t. When we speak at an event, there are generally three reasons we are talking; to influence, to inspire or to inform. For our last slide, we want to drive home the point we are making. Perhaps you could ask a question, for example;
What could you achieve if you changed your mindset and believed in yourself?
You don’t need the question written on the slide. As mentioned earlier, our audience at the back of the room might not be able to read it. How about an image that captures the sentiment on a slide?

Another option for your final slide is a call to action. How about a QR code linking to your website? For example, you could say the line, “If you are interested in any of my public courses, find the course list with the QR code below.” and have the following slide to accompany your words.

Thank you for reading this blog. I’d love to hear your feedback on “how does the size of an audience affect a presentation.“
If you’d like to know how I can help you create slides like these for your next PowerPoint presentation, check out my Services page!
To see more tips and tricks on slide design and presenting with PowerPoint, connect with me on LinkedIn.