Aspect ratios and image sizes explained
Updated October 9, 2026 · By Lee Palmer
An aspect ratio describes the shape of an image: its width compared with its height. A 1920 × 1080 image and a 1280 × 720 image are different sizes but the same shape, 16:9. Getting the shape right matters more than the exact pixel count, because a site that receives the wrong shape will crop it for you, often cutting off something important.
Common aspect ratios
| Ratio | Shape | Common sizes | Typical uses |
|---|---|---|---|
| 1:1 | Square | 1080 × 1080 | Feed posts, profile pictures, product photos |
| 4:5 | Tall portrait | 1080 × 1350 | Portrait feed posts that fill more of a phone screen |
| 3:4 | Portrait | 1080 × 1440 | Portrait posts and tablet photos held upright |
| 9:16 | Full-screen vertical | 1080 × 1920 | Stories, reels, Shorts and phone wallpapers |
| 16:9 | Widescreen | 1920 × 1080, 1280 × 720 | Video, thumbnails, presentations, monitors |
| 1.91:1 | Wide | 1200 × 630 | Preview images for shared links |
| 3:2 | Classic photo | 1800 × 1200 | Camera photos and 6 × 4 inch prints |
| 4:3 | Standard photo | 1600 × 1200 | Phone photos and tablets |
| 2:3 | Tall poster | 1000 × 1500 | Pins, posters and book covers |
| 3:1 and 4:1 | Banner | 1500 × 500, 1584 × 396 | Profile headers and banners |
Platforms update their recommended sizes from time to time. If an exact size matters, check the current help page of the site you are uploading to; the shape in the table is usually the important part.
How to work out a ratio
Divide the width and height by their largest common factor. For 1920 × 1080, both divide by 120, giving 16:9. To find a height for a given width, multiply the width by the second number and divide by the first: a 1500-pixel-wide image at 4:5 needs 1500 × 5 ÷ 4 = 1875 pixels of height.
Crop, fit or stretch
When a picture has a different shape from the one you need, there are three options. Crop fills the new shape by trimming edges and is usually the best choice for photos. Fit keeps the whole picture and adds plain bars, which suits documents, artwork and logos. Stretch forces the picture into the new shape and distorts it, so it is rarely what you want. The crop tool offers crop and fit with a live preview.
Safe zones
Many apps place buttons, captions, profile pictures or progress bars over parts of an image, and the same picture may be shown cropped in one place and in full in another. Keep faces, products and text away from the very edges, roughly the outer tenth of the frame, and the result will look right wherever it appears. For vertical 9:16 images, also keep clear of the top and bottom, where app controls usually sit.
Higher resolution is not always better
Most sites resize uploads to their own display sizes. Uploading a 6000-pixel image rarely looks sharper than a 2000-pixel one, and can take longer to upload or hit a size limit. Use the sizes in the table as a starting point, and use the resizer if the site also sets a file size limit.