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The Exact Dimensions and Grid Math for Seamless Instagram Carousels

Slide sizes, master-canvas width, seam alignment, safe margins, and export settings for pixel-perfect panorama carousels. The reference, with the math.

If you make seamless carousels, you eventually want the numbers, not the vibes. This is the reference: slide dimensions, how the master canvas scales, where the safe margins are, and what to export. If you just want to make one, start with the panorama walkthrough instead. This page is for when you care about pixels.

TL;DR — Use 4:5 portrait slides, 1080 × 1350 px, up to 20 of them. The master canvas is slide-width × number-of-slides, and every slice must be exactly that width ÷ slide count. Export above 1080px (Jodu renders up to 3840px on the long edge) so Instagram's downscale stays sharp.

Slide dimensions

A carousel's aspect ratio is set by the first slide, and Instagram applies it to all of them. Pick one and commit. For feed posts your only sane choices are:

Shape Aspect Pixel size (per slide) Notes
Portrait 4:5 1080 × 1350 Tallest the feed allows. Use this.
Square 1:1 1080 × 1080 Safe, smaller footprint in-feed.
Landscape 1.91:1 1080 × 566 Short. Avoid for panoramas, too little height.

Instagram displays everything at 1080px wide and re-compresses on upload. You can't beat 1080 on their side, but you do want to feed it more than 1080 so the downscale stays sharp (more on that below).

The slide count ceiling is 20. That's your maximum panorama width.

Master-canvas math

A seamless carousel is one wide image sliced into equal columns. The master canvas is just the slide repeated N times across:

master width  = slide width  × number of slides
master height = slide height (unchanged)

For 4:5 slides (1080 × 1350):

Slides Master canvas Aspect of the whole
2 2160 × 1350 1.6 : 1
3 3240 × 1350 2.4 : 1
4 4320 × 1350 3.2 : 1
5 5400 × 1350 4 : 1
10 10800 × 1350 8 : 1

Every slice has to be exactly master width / N wide. This is the bit people get wrong by hand. A rounding error of even one pixel per slice adds up into a visible step by the time you reach the far seams. If you're slicing manually, make your master width divide cleanly by your slide count.

In Jodu you don't compute any of this. You design on one continuous canvas and it renders each slide as an equal column at export, so the seam math is exact by construction.

Seams and safe margins

Two different margins matter, and they're easy to mix up.

Export settings

What you hand Instagram matters as much as what you designed.

Quick-reference

Recommended slide:   1080 × 1350  (4:5 portrait)
Max slides:          20
Master width:        1080 × N
Slice width:         master width ÷ N  (must be exact)
Content safe margin: ~108px from each slide edge
Grid-crop region:    center 1080 × 1080 of slide 1
Export target:       up to 3840px long edge per slide (≈3072 × 3840 at 4:5)

FAQ

4:5 portrait, 1080 × 1350 px. It's the tallest shape the feed allows, so it gives each slide the most screen space. Square (1080 × 1080) also works.

Up to 20 in a single post.

Each slide stays 1080 × 1350 (4:5). The full master image is slide-width × number-of-slides wide, for example 3240 × 1350 for 3 slides, sliced into equal 1080-wide columns.

Higher than 1080px wide per slide, so Instagram's compression stays sharp. Jodu renders each slide at up to 3840px on the long edge (about 3072 × 3840 for a 4:5 slide).


Part of a 3-part series. The panorama walkthrough covers the craft, and the beginner's guide covers the basics. Jodu handles all of the slicing math for you.

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