You can easily change the aspect ratio of your entire presentation with these basic steps
To change the slide size:
- Select the Design tab of the toolbar ribbon.
- Select Slide Size near the far right end of the toolbar.
- Select Standard (4:3 aspect ratio) or Widescreen (16:9) or Custom Slide Size.
- On the Design tab of the Ribbon, locate Slide Size in the Customize group, near the far right end of the toolbar.
- Select Slide Size, and then select either Standard (4:3) or Widescreen (16:9).When PowerPoint is unable to automatically scale your content, it prompts you with two options:
- Maximize: Select this option to increase the size of your slide content when you are scaling to a larger slide size. Choosing this option could result in your content not fitting on the slide.
- Ensure Fit: Select this option to decrease the size of your content when scaling to a smaller slide size. This could make your content appear smaller, but you’ll be able to see all content on your slide.
The 16:9 widescreen setting is the default value for new presentations you create. When you change the slide size for a presentation, the size you choose only applies to that presentation. However, you can make it easy to create a new 4:3 presentation for yourself whenever you want—by defining a custom theme that uses the 4:3 aspect ratio. See the section below named “Make a default size to start from when creating new presentations.”
Sizing applies to all slides in a presentation
Some folks have asked about resizing one slide within a presentation. PowerPoint isn’t able to do that. All slides in a presentation are the same size.