Image aspect ratios explained: 16:9, 4:3, 3:2, 1:1 and 9:16
What aspect ratios mean, which one each screen, camera and platform uses, and how to crop a picture to a ratio without stretching it.
Updated
Tools for this job: Crop Image · Resize Image · Instagram Image Resizer
An aspect ratio is the shape of a picture: its width compared with its height. 16:9 means 16 units wide for every 9 tall, whatever the actual size. Getting the shape right before resizing is what stops pictures being stretched, squashed or awkwardly cropped by the place you upload them.
The common ratios
| Ratio | Used for | Example |
|---|---|---|
| 16:9 | TV, monitors, YouTube, presentations | 1920 × 1080 |
| 9:16 | Stories, Reels, Shorts, phone screens | 1080 × 1920 |
| 4:3 | Many phone cameras, older screens, tablets | 4000 × 3000 |
| 3:2 | Most system cameras, 6 × 4 photo prints | 6000 × 4000 |
| 1:1 | Profile pictures, square posts | 1080 × 1080 |
| 4:5 | Portrait feed posts | 1080 × 1350 |
| 21:9 | Ultrawide monitors and cinema-style video (2.33:1) | 2560 × 1080 (sold as 21:9, strictly 64:27) |
Working out a ratio
Divide the width and height by their largest common factor. 1920 × 1080 divides by 120 to give 16 × 9. For sizes that do not simplify neatly, divide width by height: 1.78 is 16:9, 1.5 is 3:2, 1.33 is 4:3 and 1 is square.
Why stretching happens
Resizing a 4:3 photo to 1920 × 1080 without cropping forces it into a different shape, so everything is stretched sideways — faces look wide, circles become ovals. The fix is always the same: crop to the new shape first, then resize.
Crop to a ratio step by step
- Add the picture to Crop Image.
- Choose a preset — 1:1, 4:3, 3:2, 16:9 or 9:16 — or type exact pixel values for any other shape.
- Drag the selection over the part of the picture to keep.
- Crop and download, then resize if you need specific dimensions.
The crop is cut from the full-resolution original, so nothing is lost but the area outside the selection. Then use Resize Image with the aspect lock on to reach the exact pixel size.
Crop or pad?
Cropping removes part of the picture to fit the shape. When nothing can be lost — a screenshot, a poster, a graphic with text near the edges — the alternative is padding: fit the whole picture inside the frame and fill the leftover space with a colour. The Instagram Image Resizer offers both for social media sizes.
Converting between common shapes
- 4:3 phone photo to 16:9: you lose about a quarter of the height, a strip from the top and bottom.
- 16:9 to 1:1: you lose almost half the width, so keep the subject central.
- 3:2 camera photo to a 6 × 4 print: no crop needed — 6 × 4 is 3:2.
- 3:2 to a 10 × 8 print: 10 × 8 is 5:4, so a noticeable strip comes off the long side. Print shops crop it for you unless you do it first.
Shoot with the end in mind
If you know a photo is for a vertical Story, shoot it vertically. Cropping a 16:9 landscape photo to 9:16 throws away about two-thirds of it — and most of its detail.