4:5 aspect ratio
4:5 is the portrait shape: 4 units wide for every 5 tall, which is 0.8 as a decimal. 1080 x 1350 px is 4:5 because 1080 divided by 1350 gives 0.8, and the fraction reduces to 4:5. 6 of the image sizes on this site use it.
Where 4:5 comes from
4:5 is the tallest shape Instagram accepted in the feed for most of its history, so it became the default for anyone who wanted the most vertical space a single photo could occupy. That ceiling moved: since 29 May 2025 Instagram accepts 3:4 for single photos and carousels. 4:5 remains the shape most scheduling tools, ad templates and design presets are built around, which is why it is still the most searched of all of them.
Which platforms use 4:5
Read live from the specification data, so this list changes when a platform does. Last verified 2026-07-27.
| Platform | Asset | Size (px) | Source |
|---|---|---|---|
| Post (portrait) | 1080 x 1350 | Convention | |
| Portrait post | 1080 x 1350 | Convention | |
| Carousel | 1080 x 1350 | Convention | |
| Feed ad image | 1440 x 1800 | Convention | |
| Feed ad image | 1440 x 1800 | Convention | |
| Threads | Post image | 1080 x 1350 | Convention |
4:5 in pixels
Every row below is calculated from the ratio rather than looked up, so the heights are exact where the arithmetic is exact and rounded to the nearest whole pixel where it is not. A fractional pixel is not something a file can store.
| Width | Height | Used by |
|---|---|---|
| 1080 px | 1350 px | Instagram post (portrait), Instagram portrait post, Instagram carousel, Threads post image |
| 1200 px | 1500 px | - |
| 1440 px | 1800 px | Instagram feed ad image, Facebook feed ad image |
| 1920 px | 2400 px | - |
Cropping and letterboxing into 4:5
A landscape source cropped to 4:5 loses a lot from the sides, because you are asking a wide frame to become a tall one. If the subject is off-centre, crop by hand rather than letting a centre crop decide.
There are only two honest ways to put an image of one shape into a frame of another. Crop to fill keeps the frame full and throws away whatever does not fit, which is almost always what you want for a feed. Fit inside keeps the whole image and pads the remaining space, which is what you want when the image is a diagram, a screenshot or anything where losing an edge loses meaning. Scaling to fit without doing either, so the image is stretched, is the one option that is always wrong.
Work out a 4:5 size
Enter a width or a height and the calculator solves the other side. It runs in your browser and nothing is uploaded.
Other ratios
See the aspect ratio guide for the shapes side by side, or the full cheat sheet for every size on one page.