The short answer: design every slide at 1080 x 1350 pixels, keep the important parts 80 pixels in from the edges, and plan for 10 slides or fewer. The rest of this guide explains why, gives you eight slide-by-slide structures to copy, and lets you download a blank, correctly sized slide set.
By the TimeToPost team. Last reviewed 2026-10-10.
A carousel is one post with several slides. Instagram shapes every slide to match the first one, so you choose a single ratio for the whole post. These are the three that matter.
| Ratio | Pixels | Use it when |
|---|---|---|
| 4:5 portrait | 1080 x 1350 | Default. Most feed space, best for text-heavy slides. |
| 1:1 square | 1080 x 1080 | Photos and quote cards. Safe for scheduled posts. In the 3:4 profile grid a square is cropped to the middle 810 pixels, about 135 pixels lost on each side. |
| 3:4 portrait | 1080 x 1440 | When you post inside the Instagram app and want the grid tile to match the feed. Not for scheduled carousels: the publishing API accepts only 4:5 to 1.91:1. |
Width is 1080 pixels in all three. Wider files are scaled down, and narrower ones are scaled up and look soft. Export at exactly 1080 wide and let the height follow the ratio.
Check the numbers against the source before a big campaign, because Instagram changes its post shapes from time to time. The Instagram Help Center is the reference for what the app accepts. For what the publishing API accepts, see the Instagram content publishing documentation, which states that carousels hold up to 10 images, videos or a mix, that JPEG is the only supported image format, and that every slide is cropped to the first one, with 1:1 as the default.
In the Instagram app a carousel can hold up to 20 slides. Through the publishing API, which is how any scheduling tool posts on your behalf, the limit is 10. If you plan to schedule, design for 10 or fewer. In practice that is not a loss: most carousels read best between 5 and 9 slides, because the last slide is where people stop swiping.
There is no official safe-zone diagram for carousels, so treat these numbers as working rules derived from the sizes above. They are our recommendation, not an Instagram requirement.
The download below draws these two guides on each blank slide: the 80 pixel margin in purple and the 3:4 grid crop in grey.
Blank slide set
Files are drawn in your browser. Nothing is uploaded. Your browser may ask once to allow multiple downloads.
Open the files in any design tool as a backdrop. The guides are drawn into the PNG, so download a second set with the guides box unchecked if you want clean blanks, and export JPEG at 1080 pixels wide.
A structure is a reusable order of slides. Pick one, fill each slide with your own content, and keep one idea per slide.
Use it to teach one process that has a clear order. Works well for tutorials and setup guides.
Use it when your field has a belief you can correct with something you have seen yourself.
Use it for a visible change: a redesign, a rewritten caption, a cleaned-up workflow.
Use it for a set of tips, tools or lessons where each item stands alone.
Use it to share a real experience: a launch, a failure, a lesson from a client.
Use it for something a reader will want to come back to, such as a pre-launch or pre-post checklist.
Use it to help someone choose between two approaches, formats or tools, without claiming one always wins.
Use it to show how a product or feature works, one screenshot at a time.
Aim for one idea and at most 30 to 40 words per slide. If a slide needs more, split it in two. Put the detail in the caption, where it is also searchable. Use the same fonts, colours and margins on every slide so the swipe feels like one piece.
Need to reshape one image for several networks at once? The social media image sizes post lists the common sizes side by side. To schedule the finished carousel, read how the Instagram scheduler handles carousels.
1080 x 1350 pixels (4:5 portrait) is the safest default because it takes the most vertical space in the feed. 1080 x 1080 (1:1) also works. 1080 x 1440 (3:4) works only when you post inside the Instagram app: the publishing API behind scheduling accepts aspect ratios from 4:5 to 1.91:1, so scheduled carousels should use 4:5 or 1:1. Pick one ratio and use it for every slide.
Up to 20 slides when you post from the Instagram app. Publishing through the Instagram API is limited to 10 images or videos per carousel, which is what scheduling tools that use the API can send.
Yes in practice. Instagram crops every slide to the shape of the first one, and the API documentation says the same: carousel images are cropped based on the first image, with 1:1 as the default. Design every slide at the ratio of slide one.
The profile grid shows a taller, narrower tile than the feed. A 4:5 slide shown as a 3:4 tile loses about 34 pixels from each side of a 1080 pixel wide design. Keep the cover slide text inside an 80 pixel margin and it survives both views.
Export JPEG for anything that will be published through the Instagram API, because JPEG is the only image format the API accepts. PNG is fine for uploading in the app, but JPEG avoids a failed scheduled post.
Yes. Connect a Business or Creator account to TimeToPost, add up to 10 images or videos, write the caption and pick a time. The carousel publishes at that minute.
Finished the slides? Schedule the carousel with TimeToPost: add up to 10 images, write the caption once, and it publishes at the time you choose.
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