Aspect ratio calculator for screens and images
Helps when you resize an image or video and want to keep its shape without stretching.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter width, height and new width.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
Ratio = width ÷ GCD : height ÷ GCD, where GCD is the greatest common divisor. New height = new width × height ÷ width.
Example
Inputs: Width = 1,920 px, Height = 1,080 px, New width = 1,280 px. Result: Aspect ratio: 16:9; Decimal ratio: 1.7778; Height for the new width: 720 px.
Limits and caveats
- The new height can be a fraction; round it to the nearest pixel when you export.
Questions about this tool
What ratio is 1920 × 1080?
It is 16:9, the ratio of most screens and YouTube videos.
What ratio is an Instagram portrait post?
The 1080 × 1350 pixel size is 4:5.
Why do I see an odd ratio like 683:384?
Some resolutions such as 1366 × 768 are not exactly 16:9, and the tool shows the exact ratio.