How to Change the Slide Size in Microsoft PowerPoint

By default, new Microsoft PowerPoint presentations are created with a Widescreen (16:9) aspect ratio. This is perfectly optimized for modern laptops, desktop monitors, HD projectors, and standard televisions. However, if you are presenting on an older projector, designing a flyer meant to be printed on standard A4 or Letter-sized paper, or creating vertical content for social media like Instagram Stories, the default widescreen canvas will leave ugly black bars or crop your content awkwardly.

Fortunately, PowerPoint allows you to change the underlying dimensions of your slides at any time. You can easily switch between standard aspect ratios or dial in exact, custom measurements in inches or centimeters.

This guide explains how to change the slide size and orientation in Microsoft PowerPoint, and how to safely scale your existing content when making the change.

Step 1: Access the Slide Size Menu

The slide size settings dictate the physical boundaries of your entire presentation. Changing this setting applies to all slides simultaneously; you cannot have one widescreen slide and one square slide in the same file.

1. Open your presentation in Microsoft PowerPoint.
2. Look at the main ribbon menu across the top of the screen and click on the Design tab.
3. On the far right side of the Design ribbon, locate the Customize group.
4. Click the Slide Size button. A small drop-down menu will appear.

Step 2: Choose a Standard Size or Custom Dimensions

From the drop-down menu, you have a few immediate choices, plus a deeper customization menu.

1. If you are presenting on an older, square-style projector or monitor, click Standard (4:3).
2. If you need a specific size for printing or social media, click Custom Slide Size…
3. In the dialog box that appears, click the Slides sized for: drop-down menu. Here you will find presets for Letter Paper, A4 Paper, Banners, and more.
4. To create a completely unique canvas, type your exact desired Width and Height into the measurement boxes.
5. To change the presentation from horizontal to vertical, locate the Orientation section on the right side of the box and select Portrait under “Slides”.
6. Click OK when you are finished configuring your dimensions.

Step 3: Choose How to Scale Existing Content

If your presentation is completely blank, the size will simply change. However, if you already have text, images, or shapes on your slides, PowerPoint needs to know how to handle them as the physical canvas shrinks or expands. A prompt will appear asking you to choose between two scaling options:

• Maximize: Choose this option if you are increasing the slide size. PowerPoint will enlarge your images and text to fill the new, larger space. Note that if you are shrinking the slide, choosing Maximize will cause your content to spill off the edges of the slide, requiring you to manually resize everything.
• Ensure Fit: Choose this option if you are shrinking the slide size. PowerPoint will automatically scale down all your text, images, and shapes so that nothing falls off the edge of the canvas. This is usually the safest option.

Click your preferred scaling option, and PowerPoint will instantly apply the new dimensions to your entire presentation.