How to Change Slide Size in PowerPoint: Whitepage Guide

PowerPoint is not just for boardrooms. It’s the all-purpose tool of design that can be used for everything.

Controlling your slide dimensions is an often-overlooked detail, which can actually make a big difference.

Knowing how to change slide size in PowerPoint makes you the person whose presentation always prints perfectly, exports without distortions, and shows on a projector in HD without the messy black borders or broken pixels. How do you do this? It all starts with the Setup menu.

Why Slide Size Matters More Than You Think

PowerPoint slide dimensions and the size of your canvas dictate the quality of your presentation design.

If you ignore this setting, three things can go wrong:

1. Blurry exports. If your slide size is small, exporting it as a JPG for social media will result in a low-resolution image. 
2. Wasted screen real estate. Presenting a 4:3 deck on a wide-screen monitor leaves black bars on the sides of your content.
3. Print disasters. A standard slide doesn’t match the A4 paper format. If you try to print a default presentation, you’ll get unremovable white margins.

Setting the correct PowerPoint presentation dimensions from the start will save you all of these headaches. 

Default PowerPoint Slide Sizes (16:9 vs 4:3)

Before customizing, let’s understand the two native PowerPoint slide sizes.

• Widescreen (16:9)

This is the modern standard. It mimics the shape of HD televisions, laptops, and almost all conference room projectors. Since PowerPoint 2013, this has been the default setting. 

Use for: Boardroom presentations, YouTube videos, Zoom/Teams meetings.

• Standard (4:3)

This is the "boxy" format of the past, but it’s still relevant for specific use cases. 

Use for: Content for iPads (which have a 4:3 aspect ratio), printing slides on US Letter paper.

How to Change Slide Size in PowerPoint (Quick Guide)

Here is the workflow in a nutshell:

1. Open your presentation and click the Design tab on the top ribbon.
2. Click the Slide Size button.
3. Select Standard (4:3) or Widescreen (16:9).
4. For precise PowerPoint slide dimensions (like A4 or Instagram), select Custom Slide Size and enter your values.

Now let’s look closer at each step. 

Adjusting PowerPoint Slide Dimensions: Step-by-Step

Here is the safe, professional way to customize your canvas.

Step 1. Open the Slide Size Menu

Open the Design tab on the top ribbon. Look for the Slide Size button.

Step 2. Choose “Custom Slide Size”

Click Custom Slide Size at the bottom of the dropdown menu. This opens the dialogue box with controls for the measurements and the orientation.

Step 3. Select Preset or Enter Custom Dimensions

In the "Slides sized for" dropdown, you’ll find presets for paper (A4, Letter, Ledger).

Pro tip: Ignore the dropdown. For digital formats, you can type directly into the Width and Height boxes. 

Step 4. The "Maximize vs. Ensure Fit" Trap

Once you click OK, PowerPoint will throw a pop-up asking you to choose between Maximize and Ensure Fit.

This is where most users break their presentation. The names are misleading. Here is what they actually do:

❌ Maximize – this option crops and stretches your content to fill the canvas.

This will distort your photos or crop your text off the edges. Only use this if your slides contain nothing but an abstract background.

✅ Ensure Fit – this option scales your content until it fits inside the new slide boundaries.

Nothing gets cut off, no images get distorted. You might get white space on the sides, but your data and design remain intact.

Pro tip: if "Ensure Fit" leaves you with white space, don't fix every slide manually. Go to View > Slide Master. Adjust the layouts here to fix the entire presentation at once. 

Recommended Slide Sizes for Every Use Case

Here’s how to use the exact correct PowerPoint slide size dimensions for anything you’re building.

Standard Presentation Sizes

For screens, projectors, and virtual meetings.

‍

Print & Documents

❌ Warning: PowerPoint’s built-in "A4 Paper" preset is very misleading. It defaults to 10.83 x 7.5 in (slightly smaller than a real A4 sheet) to account for office printer margins. If you send this file to a professional printer, you’ll get unwanted white borders.

For edge-to-edge printing, use these True Custom dimensions:

‍

Social Media Formats

PowerPoint is an excellent tool for social graphics. When you define the PowerPoint slide dimensions clearly to fit your needs, you ensure high quality.

‍

Posters & Academic Materials

PowerPoint is the standard design tool for 85% of the scientific community. To design large-format print materials with it, first, check your requirements. A US conference often requires a 36" x 48" board, while European ones commonly use an A0 frame.

‍

Pixel to Centimeter Conversion in PowerPoint

No need to convert units manually! PowerPoint automatically converts the value based on your system’s DPI (Dots per Inch). For example, to design for Instagram (1080px) in a centimeter-based PowerPoint, simply type "1080 px" into the width box and let the program do the math. 

The "Export Trap"

If you’re designing graphics to export, PowerPoint often compresses the output resolution.

To guarantee a crisp 1920 x 1080 (Full HD) export on a standard Windows machine (96 DPI), you must set your PowerPoint slide dimensions to these numbers:

• Width: 20 Inches (50.8 cm)
• Height: 11.25 Inches (28.575 cm)

Designing at this larger physical size forces PowerPoint to export a high-definition image without blurring the text.

Advanced Slide Formatting Tips

Changing the PowerPoint slide size after you’ve designed the slides is destructive. It moves text and stretches images. Here’s how professionals fix the damage.

The "Blank Deck" Hack

Resizing an existing presentation often results in scattered content. 

Pro tip: Don’t resize the populated deck.

1. Open a blank presentation.
2. Set the slide size to your desired format (e.g., A4) first.
3. Copy your slides from the old deck and paste them into the new one.
4. Select "Keep Source Formatting" or "Use Destination Theme" depending on your need. This way, PowerPoint "reflows" the content into the new container cleanly.

The "Mixed Orientation" Trick

Users ask: "How do I make just one slide Portrait?"  In reality, you can't. A PowerPoint file must be all Landscape or all Portrait.  

Pro tip: Link two files.

1. Create your main deck (Landscape).
2. Create a second deck containing only specific portrait slides.
3. In the main deck, create a hyperlink pointing to the portrait file. During a slideshow, clicking the link will open the portrait slide. Simply exit that deck to return to the main presentation.

Fix Distorted Images 

If you accidentally clicked Maximize and now your team photos look squashed or stretched:

1. Select the distorted image.
2. Go to the Picture Format tab.
3. Click Reset Picture > Reset Picture & Size. 

The "56-Inch Trap" (And How to Fix It)

1. PowerPoint limits slide size to 56 inches (142.24 cm). 
2. For larger banners (e.g., 72" x 36"), design at 50% scale (36" x 18"). Then instruct the print shop to "print at 200% scale." Make sure to use high-res images.

Need a Custom Slide Format or Branded Layout?

Resizing a presentation often reveals the cracks in a company’s template. Logos distort, fonts revert to default, and branding breaks.

At Whitepage, we provide bulletproof presentation design services building decks that adapt to any format, be it a 16:9 pitch deck or a print-ready A4 report. If you need a presentation system that works as hard as you do, we can help.

‍