How to use the aspect ratio calculator
Type the width and height of an image, video or screen into the first row. The calculator reduces it to the simplest ratio, shows the decimal value, and names the closest standard ratio if there is one. Then type a width or height in the second row — the other side updates automatically so the proportions match. Preset buttons fill in the common ratios; hover over one to see where it is used.
Pixel values are rounded to whole numbers, which is what image editors and video encoders accept. The CSS line at the bottom is ready to paste into a stylesheet: the aspect-ratio property reserves the right amount of space for an image or embed before it loads, which prevents layout shift.
From ratio to pixels
Most of the time you know the ratio a platform wants and the width your design allows. Pick the ratio, type the width, and read off the height. To actually change an image to that shape, crop it with the Image Cropper using the matching preset, then scale it to the calculated size with the Image Resizer. Cropping first keeps subjects undistorted; resizing to a different ratio without cropping stretches the picture.
Common aspect ratios at a glance
| Ratio | Decimal | Common sizes | Typical use |
|---|---|---|---|
| 16:9 | 1.778 | 1280×720, 1920×1080, 3840×2160 | Video, monitors, YouTube |
| 9:16 | 0.5625 | 1080×1920 | Stories, Reels, TikTok |
| 4:3 | 1.333 | 1024×768, 1600×1200 | Tablets, older displays |
| 3:2 | 1.5 | 6000×4000, 3000×2000 | Camera photos, 6×4 prints |
| 1:1 | 1 | 1080×1080 | Square posts, avatars |
| 4:5 | 0.8 | 1080×1350 | Instagram portrait |
| 1.91:1 | 1.91 | 1200×630 | Open Graph link previews |
For the reasoning behind each ratio and how to change one without distortion, read image aspect ratios explained.