Instagram Aspect Ratio Calculator

By the RatioForge team · Last updated July 2026

Use this Instagram aspect ratio calculator to choose the right dimensions for feed posts, portrait crops, Reels and Stories. Instagram supports several shapes, so the best ratio depends on where the asset will appear. A square post is safe, a 4:5 portrait post fills more of the feed, and a 9:16 video fills the screen in Stories and Reels.

Instagram calculator

px
px
Ratio
1080 1350 4:5
Drop an image to read its ratio

Instagram sizes by placement

Size / ratioLabelUse-case
1080×10801:1Square feed post, carousel slide
1080×13504:5Portrait feed post with maximum vertical feed space
1080×5661.91:1Landscape feed post
1080×19209:16Stories and Reels
320×3201:1Profile picture source

Instagram formulas

Worked example. Say your source photo is 1440 px wide and you want a 4:5 portrait post. Height = 1440 × 5 ÷ 4 = 1800 px, so 1440×1800 is a valid 4:5 crop that Instagram downscales to its 1080 px display width (1080×1350). For a landscape post at the widest allowed shape, a 1080 px-wide image needs 1080 ÷ 1.91 ≈ 566 px tall. And a 9:16 Reel from a 1080 px-wide frame is 1080 × 16 ÷ 9 = 1920 px tall.

Which Instagram ratio should you choose?

Instagram is not one ratio. Feed posts, profile pictures, Stories and Reels all behave differently. Choosing the placement first prevents you from exporting one image and then discovering that Instagram crops the important part.

For organic reach and feed presence, 4:5 is often the strongest image format because it takes up more vertical space than a square while still fitting the feed. For full-screen video, use 9:16. For reusable carousels or profile assets, square 1:1 is still simple and safe.

A designer making a carousel may want 1080×1080 for predictable square slides. A creator optimizing a single feed graphic may prefer 1080×1350 because it occupies more height in the feed. A Reel or Story should move to 1080×1920 because it is consumed full-screen. Those choices are different enough that one generic export rarely fits them all.

Avoid reusing one file everywhere: a 16:9 YouTube thumbnail can become cramped or cropped on Instagram, and a 9:16 Story can be too tall for a feed post. If your source material is widescreen, start from the 16:9 calculator; for Reels and Stories, work in the 9:16 calculator; and for recommended dimensions on every platform, see the social media image sizes guide.

Carousels lock to the first slide's ratio

A carousel is not a set of independent images — every slide inherits the aspect ratio of the first one you add. If slide one is a 1:1 square and slide two is a 4:5 portrait, Instagram does not switch shapes between them; it forces the 4:5 slide into the square and centre-crops whatever falls outside, so the top and bottom of that portrait art disappears. The safest habit is to commit the whole carousel to a single canvas before you start. Export every slide at 1080×1350 (4:5) if you want maximum feed height, or 1080×1080 (1:1) if any slide needs the full square — then design each frame to fit that box exactly rather than trusting Instagram to reconcile mixed ratios for you.

Instagram's aspect-ratio limits

The feed accepts a fixed range of shapes: from 1.91:1 landscape at the wide end to 4:5 portrait at the tall end. Anything outside that window is cropped to the nearest limit — a 16:9 upload is squeezed toward 1.91:1, and a full 9:16 graphic is trimmed down to 4:5, both losing content in the process. Stories and Reels are the exception: they live outside the feed and use the full 9:16 frame.

PlacementRatioPixelsLimit
Landscape post1.91:11080×566Widest the feed allows
Square post1:11080×1080Never cropped in the grid
Portrait post4:51080×1350Tallest single image allowed
Reel / Story9:161080×1920Full-screen, outside the feed

Notice the shared 1080 px width: Instagram displays feed images at a 1080 px cap, so uploading anything larger simply downscales to fit. Exporting at exactly 1080 px on the short edge avoids an extra resample and keeps edges sharp. The diagram below shows the three feed-relevant shapes drawn to scale from a common width.

1:1 square 4:5 portrait 9:16 Reel

The profile grid crops 4:5 to 1:1

There is one crop that surprises people even after they get their post dimensions right: the profile grid always renders posts as 1:1 square thumbnails, no matter how they were published. A 4:5 portrait that looks perfect in the feed is centre-cropped to a square in the grid, so its top and bottom edges are hidden in that preview. The full 4:5 crop reappears the moment someone taps into the post. The practical rule is to keep your subject — a face, a product, a headline — near the vertical centre of a portrait post, so it survives both the square grid preview and the taller in-feed view without important detail sliding off either edge.

Frequently asked questions

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