The ideal size for a standard Instagram feed post is 1080 x 1080 pixels in a 1:1 square ratio. For Reels and Stories, 1080 x 1920 pixels at a 9:16 aspect ratio gives you full-screen coverage without any cropping.

Why Instagram Post Dimensions Actually Matter

Getting the size right sounds minor until you upload something and watch it get cropped in the worst possible spot. Instagram compresses images automatically, but that only works cleanly when your file matches the platform's native dimensions.

If the dimensions are off, you'll typically see:

•      Blurry or pixelated visuals after Instagram compresses the file.

•      Awkward cropping that cuts off faces, logos, or key text.

•      Reduced reach, the algorithm favours content that displays cleanly. 

What Is the Best Size for Instagram Feed Posts?

Instagram supports three aspect ratios for regular feed posts:

•      Square (1:1): 1080 x 1080 px. The safest all-round option. Works well for product shots, quote cards, and brand graphics.

•      Portrait (4:5): 1080 x 1350 px. Takes up more vertical space in the feed, so it gets more visual attention. Many brands prefer this for organic posts.

•      Landscape (1.91:1): 1080 x 566 px. Good for wide-angle photography and banner-style images, though it occupies less feed space compared to portrait. 

For most brands, the 4:5 portrait format performs best. It occupies more screen space, which means fewer people scroll past before registering your content.

What Is the Best Size for Instagram Reels?

Reels use a vertical full-screen format. The correct dimensions are 1080 x 1920 px at a 9:16 aspect ratio. Keep important elements within the central 1080 x 1420 px area; the top and bottom 250 px are covered by Instagram's UI (username bar, captions, and action buttons).

If you shoot on your phone in portrait mode, you're already at the right ratio. Export at full resolution before uploading to avoid compression quality loss.

What Is the Best Size for Instagram Stories?

Stories use the same dimensions as Reels 1080 x 1920 px at 9:16. They disappear after 24 hours unless saved to Highlights. Keep your main content in the central 1080 x 1420 px zone. The top and bottom 250 px are taken up by Instagram's interface, so any text or CTAs placed there will get hidden.

Instagram Post Size Reference Table

Source: VIRAL-IMPACT

What About Instagram Carousels?

Carousels support the same three formats as regular feed posts: square, portrait, or landscape. One rule: all slides in a carousel must use the same ratio. Mixing different aspect ratios inside a single carousel triggers automatic cropping on certain slides.

Tips for Getting the Right Size Every Time

A few habits that make a real difference:

•      Design in Figma or Canva: both let you set exact pixel dimensions before you start, so there's no guessing at export time.

•      Export at 72 DPI: going higher doesn't improve visual quality on screen and just adds file size.

•      Keep your file under 30 MB: Instagram recommends this limit to avoid compression artefacts on images.

•      Use JPG for photos, PNG for graphics: PNG retains sharp edges on text and logos, which matters a lot for branded content.

 If you're posting regularly for a brand, having a fixed template for each format saves a lot of time and keeps your social graphics consistent across every placement.

The Bottom Line

Using the right Instagram post size is not just about aesthetics; it affects how your content looks to the algorithm and how it lands with someone scrolling through their feed. Stick with 1080 x 1350 px for feed posts and 1080 x 1920 px for Reels and Stories. Keep key elements out of the edge zones, and your uploads will look intentional every time.

If you're building a brand that needs to look sharp across every social channel, a strong brand identity is what ties your visuals together. And if you're figuring out your broader content strategy, the team at Viral-Impact works with early-stage startups to build organic growth systems that actually deliver results.