Why would anyone want to change the slide size in PowerPoint? You open a file, it’s the perfect 16:9 (no 4:3 fans here!), and you get stuck in, right? Well, it depends what you’re using PowerPoint for…

Presentations are a powerful tool for communicating with your audience. But if you’re making presentations, the chances are you’re also looking for other ways to get your message out there. Perhaps you want to share news on your social media feeds, present a poster at a conference, have downloadable brochures on your website, or create business cards to hand out to unsuspecting members of the public.

You might be thinking, that sounds great, but I don’t have the tools to do all that! Would you believe me if I told you can do all this and more in good-old-PowerPoint?

PowerPoint is easy-to-use, quick to edit, and is super versatile. The feature that makes creating all these different materials possible is the ability to change the size of PowerPoint slides to your desired dimensions. ‘But how?’ I hear you cry. Well, cry no more! In this blog post I’ll teach you how to change slide size in PowerPoint.

If you’re a Google Slides user who’s wandered into the wrong blog post – this one on changing slide size in Google Slides might be what you’re looking for.

How to change slide size in PowerPoint

Quick guide:

  • In the Design tab choose Slide Size. The highlighted box shows the current dimensions of your slides.
  • In the Slide Size drop down, select Custom Slide Size.
  • Select the slide size you want to use.


To know what to change, you need to know where you’re starting. When you open a brand new PowerPoint file, the standard slide dimension is widescreen (16:9). This is ideal for presentations because it matches the size and proportions of most modern screens.

screenshot of PowerPoint showing the Slide Size drop down menu

To check your slide dimensions head to the Design tab then choose Slide Size. The highlighted box shows you the current dimensions of your slides.

To change your slide size, under the Slide Size drop down, select Custom Slide Size.

Same as above but with the Custom slide size option highlighted

A pop-up box appears, and you can customise the slide size to suit your needs.

What’s helpful is that PowerPoint already has options built in for standard formats, such as Letter paper and A4, so you don’t have to spend time searching the web for the dimensions you need.

Slide size pop up

Not every combination of width and height is available in this drop down (including the dimensions for popular social media sites). So if you need a truly custom slide size, you can directly input your measurements. Select Custom from the drop-down list and type in the Width and Height you need.

Slide size pop up with 'Slides sized for:' drop down open

PowerPoint will ask you if you want to ensure fit or maximize fit. Typically you would choose to maximise when increasing the size of your slides, and ensure fit when decreasing slide size.

pop up described in text

Maximise will increase the size of any existing content on the slide, but as a result, all the content might not fit on the slide. Ensure fit scales down the size of existing content making it appear smaller but ensuring all the content fits on the slide. This is why it’s best to set the slide size right at the beginning and then you don’t need to worry about this.

After you’ve made your selection, select OK, and hey presto, you’ve done it.

For this example, we’ve chosen the size of a regular square Instagram post.

screenshot of a square PowerPoint slide with slide size pop up

Converting aspect ratio to dimensions

Just a side note on working out what slide size you need for creating social media posts. When you look up dimensions for an Instagram post, the most popular Google results tell us it’s 1080px by 1080px, but as you can see in the screenshots above, it looks like PowerPoint wants us to input our dimensions as cm. This can be a little confusing, especially for us non-designers out there who don’t know our pixels (px) from our points (pts). There are lots of websites online that can help you convert your measurements, like here – www.unitconverters.net. However, it’s a little know fact that you can enter dimensions in cm, inches or pixels and PowerPoint will convert it for you! Just type the numbers, then a space and then the unit abbreviations (cm, in, px). For a comprehensive guide on all social media image sizes check out this article by Brandwatch.

A regular Instagram post is a square, so that’s easy as the ratio is 1:1, meaning the width is the same as the height. With rectangles, the ratio of width to height will differ. A LinkedIn post for example, can either be portrait 1080 x 1350 or landscape view at 1280 x 720. So for the portrait the ratio is 4:5 and landscape is approximately 16:9. Don’t let this intimidate you. If you divide both sides (width and height) by the same amount you guarantee the ratio will stay the same.

If you’re entering slide size details as centimetres make sure you consider the overall slide size in cm as this will affect the size of an image export, which in turn can affect the quality of your exported image. Put simply an Instagram post made on a 2cm by 2cm slide will be poorer quality than one made on a 10cm by 10cm one. We have a helpful blog post that goes into much more detail on Picture size and resolution in PowerPoint.

Now that you’re a pro on how to change PowerPoint slide size, let’s go through some examples of the awesome things you can do with this new knowledge. But before we do that just a note – there are dedicated software to create a bunch of the things we’ve mentioned in this article. If you have access to it, that’s amazing! Use it! But for many of us, PowerPoint is one of our only design tools and purchasing a handful of other programs isn’t on the cards, so we need to get the most out of PowerPoint that we can.

Academic posters

For researchers and students alike, creating academic posters can be one of the more gruelling tasks on your to-do list. For most people that’s because they struggle to make posters look beautiful and engaging meaning people miss out on reading your incredible work! With your new knowledge of how to change slide size in PowerPoint, you can start making A4 and A3 posters in PowerPoint.

Some things to remember…

A poster should never be an impenetrable wall of text but a visual summary of your work. It should be concise with plenty of white space, accessible, with a clear and logical layout. A great poster is a conversation starter that drives the audience to learn more.

On the left of the image is a dense, text filled poster. On the right is the same poster with a face lift, less text, better visuals and more cohesive design.

We have a whole blog post on to how to create beautiful and effective academic posters in PowerPoint, so make sure you give that a read for more tips and tricks and a couple of cheeky freebies!

Social media posts

Once you know how to change slide size in PowerPoint you can create graphics for all your social media channels. Whether it’s for Instagram, LinkedIn, Facebook or Twitter… sorry X, we’ve got you covered. Check out this blog post on how to create social media posts in PowerPoint, from colours to image manipulation to animation! In the rapidly changing world of social media, you need to strike a balance between compelling visuals and concise messaging, to get your audience to stop scrolling, pay attention and remember your message.

example LinkedIn image that you can make in PowerPoint

If you have mind-blowing stats to share, but struggle with data visualisation, spend a little time working on your data vis skills before getting started. Start here.

And, thanks to the wonders of PowerPoint animation, you’re not just limited to static social media materials when creating in PowerPoint. Dynamic GIFs are a cool way to captivate your audience and are easier to make than you might think. When creating your GIF, remember to keep it short to capture and keep attention, and focus on smooth transitions for a polished, professional result.

animated GIF suitable for Instagram stories showing different house plants and tips for care.

Honourable mentions

Here’s a few more handy blog posts to check out for extra tips and tricks on creating anything BUT presentations in PowerPoint!

How to get the most out of PowerPoint and PDFs

How to make an infographic in PowerPoint

How to make a PowerPoint memory game

You’ve made it – now you know how to change slide size in PowerPoint and hopefully are inspired to use PowerPoint to create more than just presentations.

Leave a comment
Written by

Harriet Jones

Communication consultant

View Harriet Jones's profile

Related articles

    Leave a Reply

    Join the BrightCarbon mailing list for monthly invites and resources

    Tell me more!

    Throughout all stages of this project we have had a world class experience. The team was uber-responsive and open to feedback and collaboration to ensure we were getting the best presentation possible.

    Marc Chaanine Jamaica Bearings