Aspect ratios, and why your photo keeps getting cropped

19 September 2026 · 3 minute read

An aspect ratio is simply the shape of a rectangle: width compared with height. A photo 3000 pixels wide and 2000 tall has a 3:2 ratio. It says nothing about size; a 300 × 200 thumbnail has the same ratio. And almost every “why did my picture get cut off” problem is a ratio problem.

Cameras and screens disagree

Different devices settled on different shapes for different reasons:

Whenever an image travels from one shape to another, something has to give. Either the edges are cut off, or empty bars are added, or the picture is stretched. Platforms almost always choose to cut.

How much a crop really takes

People tend to underestimate this. Take a landscape 3:2 photo and crop it to a 4:5 portrait. The height stays the same, but the width has to shrink to 4/5 of the height, when it was 3/2 of it. That keeps only about 53 percent of the original width. Nearly half the picture goes.

Prints have the same problem. A 3:2 photo printed at 8 × 10 inches, a 4:5 ratio, loses about a sixth of its length. A 3:2 photo printed at 6 × 4 inches loses nothing, which is not a coincidence: 6 × 4 prints exist because they match film.

The arithmetic is straightforward. For a given width, the matching height is the width multiplied by the second number and divided by the first. For 1080 pixels wide at 4:5, that is 1080 × 5 ÷ 4 = 1350. StatGarden's aspect ratio calculator does these sums both ways if you would rather not.

Where automatic crops go wrong

When a platform crops for you, it usually takes the centre. That is fine for a single subject standing in the middle. It fails for:

• Group photos, where people at the ends lose shoulders, arms or entire bodies.
• Off-centre compositions, which photographers use deliberately and platforms undo.
• Text near the edges of graphics, posters and slides.
• Profile photos where the head sits high in a tall portrait, leaving a centred square of torso.

Some platforms also show a different crop in the feed than on your profile grid, or a different one on phones than on computers. And for stories and vertical video, the top and bottom of the frame are covered by the platform's own buttons and captions, so text placed there disappears even though it technically is not cropped.

Take control of the crop

The fix is to hand the platform an image that is already the right shape, so it has nothing to cut. There are two ways to change the shape yourself.

Crop deliberately. Use a crop tool locked to the target ratio and place the frame where you want it. You decide what is lost. For a group photo going into a square, that might mean moving the frame down so heads are not trimmed, or accepting that one edge goes.

Pad instead of cropping. When nothing can be lost, add space to change the shape. A wide photo on a square post with bars above and below, in white, a colour, or a blurred copy of the photo, shows everything. The square padding tool does this in one step, and it is the standard approach for product photos on marketplaces that insist on squares.

Think about the shape before you shoot

The easiest crop is the one you do not need. If you know a photo is headed for a portrait post, turn the phone. If it is for a 16:9 slide, leave room around the subject. Most phone cameras can shoot in 1:1 or 16:9 directly, and even if you shoot in the default 4:3, simply leaving space around the subject means any crop later has room to work.

Numbers change; shapes rarely do

Platforms adjust their recommended pixel sizes every so often, and grids occasionally change shape. It is worth checking the current recommendation before a big campaign. But the underlying ratios, square, 4:5, 16:9, 9:16, have been remarkably stable, and an image cropped deliberately to the right shape will survive most of those changes.