Aspect ratio is the proportion of width to height. Enter a resolution below to see the simplified ratio, and add a target width to scale it while holding the same shape.
How to calculate aspect ratio
Divide the width and height by their greatest common divisor to get the simplest whole-number ratio. To resize without distortion, multiply the new width by the original height divided by the original width. Keeping the ratio avoids black bars and stretching when content meets a display.
Common aspect ratios
| Ratio | Example resolution | Use |
|---|---|---|
| 16:9 | 1920 x 1080 | HD / 4K video, most displays |
| 16:10 | 1920 x 1200 | Some monitors and projectors |
| 4:3 | 1024 x 768 | Legacy, some signage |
| 21:9 (64:27) | 2560 x 1080 | Ultrawide |
Frequently asked questions
How do I calculate aspect ratio?
Divide width and height by their greatest common divisor. 1920 by 1080 has divisor 120, giving 16:9 (1.778 to 1).
What is the aspect ratio of 1920x1080?
16:9, the standard widescreen ratio. 3840 by 2160 and 1280 by 720 are also 16:9.
How do I resize while keeping the ratio?
Multiply the new width by original height divided by original width. 1920 by 1080 to 1280 wide gives 720 high.
What are common display aspect ratios?
16:9 is standard; 21:9 and 64:27 are ultrawide; 4:3 is legacy; 16:10 on some monitors. Match content and display to avoid bars or stretching.
Why does my image look stretched?
The source ratio does not match the display and is forced to fill it. Keep the ratio when scaling, or set the display to letterbox.
Matching sources to displays? Key Digital video processing solutions and matrix switchers scale and format signals for any screen. Find a dealer to spec your project.