How to Make Instagram Posts Different Sizes

Tired of Instagram awkwardly cropping your photos or shrinking your best shots into a tiny square? You're not alone. Mastering Instagram's different post sizes is one of the fastest ways to make your feed look more professional and capture more attention. This guide will walk you through exactly how to create and upload Instagram posts in various sizes, from a single eye-catching portrait image to dynamic multi-size carousels.

Understanding Instagram's Main Feed Post Sizes

Before you can start creating differently sized posts, you need to understand the language of aspect ratios. An aspect ratio is simply the relationship between the width and height of an image. Instagram is quite specific about what it supports in the main feed. If your image doesn't fit one of these, the app will force you to crop it.

Here are the three foundational aspect ratios for the Instagram feed:

• Square (1:1): This is the classic Instagram format. The width and height are equal. The ideal pixel size is 1080 x 1080 pixels. It's a safe, clean option that always looks good on your grid profile view.
• Portrait (4:5): This is the tallest vertical format allowed in the feed. The height is noticeably greater than the width. The optimal pixel size is 1080 x 1350 pixels. This format is a marketer's favorite for a very good reason.
• Landscape (1.91:1): This is the widest horizontal format. The width is almost twice the height. A common pixel size is 1080 x 566 pixels. While great for scenic shots, it's often the least effective for engagement.

Why You Should Be Using the 4:5 Portrait Size

If you take away just one thing from this article, let it be this: start using the 4:5 aspect ratio whenever possible. When a user is scrolling through their feed, a taller 4:5 post takes up significantly more physical screen space than a 1:1 square or a 1.91:1 landscape image. More screen real estate means your content is literally bigger and more in-your-face, making it harder to scroll past without noticing.

This increased visibility can lead to more "thumb-stopping" moments, which often translates to higher engagement - more likes, comments, and saves. While square posts are dependable, portrait posts are designed for impact.

Method 1: Using Instagram's Built-In Resizing Tool (The Quick Way)

Instagram has a basic resizing feature directly in the app. This is the fastest way to post a non-square photo if it already has an acceptable aspect ratio. It doesn’t give you precision control, but it works in a pinch.

Here’s how to do it:

1. Open Instagram and tap the + icon to create a new post.
2. Select your image or video from your camera roll. By default, Instagram will present it as a 1:1 square.
3. Look for the expand icon (two arrows pointing to the corners) in the bottom-left corner of the image preview.
4. Tap this icon once. This will toggle the post between the default 1:1 square crop and its original aspect ratio (as long as it's within Instagram's landscape or portrait limits).

The Catch: This method is all-or-nothing. You can't fine-tune the crop. If your photo is super wide, it will toggle to the 1.91:1 landscape. If it's a tall portrait shot, it will fit into the 4:5 frame. If the original aspect ratio is outside those limits, you'll still be forced to crop. This is why learning to resize your images before uploading is so valuable.

Method 2: Resizing Photos Before You Post (The Professional Way)

To have complete creative control, the best practice is always to resize and crop your images before you open Instagram. This allows you to frame your shot perfectly and guarantee it looks exactly as you intend. You can use anything from free mobile apps to professional desktop software.

Using a Free Tool like Canva

Canva is one of the most popular and user-friendly design tools, and it's perfect for quickly resizing images for Instagram.

Step-by-Step Instructions:

1. Go to Canva's website or open the mobile app.
2. On the home page, click "Create a design" and then select "Custom size" at the bottom of the dropdown.
3. A sizing box will pop up. For a portrait post, enter 1080 for the width and 1350 for the height. Make sure the unit is set to "px" (pixels). Click "Create new design."
4. This gives you a blank canvas at the perfect 4:5 aspect ratio.
5. From the left-hand menu, select "Uploads" and upload the photo you want to use.
6. Once uploaded, drag your photo onto the canvas. You can now drag the corners to resize it and move it around to position it perfectly within the 4:5 frame.
7. When you're happy with the composition, click the "Share" button in the top right, then select "Download." Choose a high-quality file type (PNG or JPG) and download it to your device.

Your photo is now saved in the perfect dimensions, ready to be uploaded to Instagram without any forced cropping.

Using Photo Editing Software (Adobe Lightroom or Photoshop)

If you're already using professional software, the process is even more direct.

In Adobe Lightroom:

1. While in the Develop or Library module, select the Crop tool (the rectangle icon on the right-hand panel, or press the 'R' key).
2. Next to "Aspect," click the dropdown menu (it often says "Original" or "As Shot").
3. From this list, select 4 x 5 / 8 x 10. This locks the crop box to the perfect portrait ratio.
4. Drag the corners and move the box to frame your subject exactly how you want. Click "Done."
5. Export your image as usual. It's now perfectly formatted.

In Adobe Photoshop:

1. Open your image.
2. Select the Crop Tool from the left-hand toolbar.
3. In the tool options bar at the top, click the aspect ratio dropdown (it may say "Ratio").
4. Choose 4 : 5 (8 : 10) from the presets.
5. Adjust the crop box to frame your shot, then press Enter to apply the crop.
6. Go to "File" > "Save a Copy" or "Export" to save your resized image.

Method 3: Creating a Carousel with Posts of Different Sizes

Have you ever seen an Instagram carousel that seems to flow seamlessly from a portrait photo to a wide landscape photo in the next slide? It’s a clever illusion, and it's easier to create than you might think. Instagram requires every slide in a carousel to have the same aspect ratio. The trick is to place your differently sized images onto a uniform background canvas.

Here’s the step-by-step method using Canva, since it's the easiest for this task.

Step 1: Choose Your Base Size

First, decide on the aspect ratio for your entire carousel. We strongly recommend making the base size 4:5 (1080 x 1350 px) to maximize your screen real estate for every slide.

Step 2: Create a Multi-Page Design in Canva

1. In Canva, create a custom design with the dimensions 1080 x 1350 px.
2. You'll now have a blank vertical canvas. Use the "Add page" button below your canvas to create as many new slides as you need for your carousel (e.g., if you have 5 photos, create 5 blank pages). Each page will be a perfect 1080 x 1350 px canvas.

Step 3: Place Your Images on the Canvases

1. Go to the "Uploads" tab and upload all the photos for your carousel.
2. For a portrait photo: If you have a photo that's already in a 4:5 aspect ratio, drag it onto one of the pages and resize it to fill the entire canvas.
3. For a landscape photo: Drag your wide photo onto a different blank canvas. Instead of stretching it to fit, simply center it on the page. This will leave empty space (padding) above and below the image. You can leave this whitespace looking clean and minimalist, or you can change the background color of the canvas to match your brand.
4. For a square photo: Do the same. Drag your 1:1 image onto a blank 4:5 canvas and center it, leaving padding at the top and bottom.

Step 4: Download and Post

When you've placed each of your photos onto its own 4:5 canvas, click "Share" > "Download." Make sure you choose to download All pages. This will save your carousel slides as individual image files, all perfectly sized to 1080 x 1350 px.

Now, when you upload them to Instagram and select them in order, it will appear as if you're swiping between different-sized images, when in reality, you're just looking at different images placed on a consistently sized background.

Final Thoughts

By moving beyond Instagram's restrictive default square, you gain massive creative freedom. Understanding how to use the 4:5 portrait mode to capture attention, and how to craft mixed-size carousels to tell a richer story, gives you a professional edge. Resizing your content beforehand is a small extra step that makes a huge difference in the final look and impact of your feed.

As you start creating content in all these different formats - Reels, Stories, and now perfectly sized portrait posts - keeping your content strategy organized can quickly become a challenge. To help with that, we built Postbase from the ground up for the way social media actually works today. Our visual calendar lets you see exactly what's going live across all your platforms, while our video-first scheduler handles Reels, TikToks, and Shorts without the format headaches you find in older tools. It lets you plan and publish your carefully crafted content with confidence.