Aspect ratio
–
Resized
–
| Common sizes at this ratio | Width × height |
|---|
Divide the width and height by their greatest common divisor. For 1920 × 1080 that’s 120, giving 16:9.
New height = new width × height ÷ width
New width = new height × width ÷ height
To shrink a 1920 × 1080 video to 1280 wide: 1280 × 1080 ÷ 1920 = 720, so the new size is 1280 × 720.
The shape of a picture or screen: its width compared with its height. 1920 × 1080 is 16:9, the shape of most TVs and YouTube videos; 1080 × 1350 is 4:5, Instagram's tall post size.
Keep the same aspect ratio. Enter the original width and height, then the new width you want; the calculator gives the matching height (or enter a new height to get the width).
Some screen sizes aren't an exact common ratio: 1366 × 768 is very close to 16:9 but not exactly. The calculator shows the exact ratio and the nearest common one.
16:9 for video and screens, 9:16 for Stories, Reels and TikTok, 1:1 for square posts, 4:5 for Instagram portrait posts, 4:3 for older screens and tablets, 3:2 for camera photos, and 21:9 for ultrawide monitors.