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Aspect ratio calculator
Preserve the correct proportions by calculating a width or height from a custom or predefined aspect ratio.
- 100% local
- Instant
- Free
- No account
- Works offline
Reference dimensions
Target dimension
Enter positive dimensions only.
Simplified ratio
Proportional dimensions
Why use this tool?
Calculate proportional dimensions for an image, video or screen without distorting the original format. Enter a reference ratio or dimensions, then provide a new width or height.
Smart processing
Prepare and transform images directly in your browser without additional software.
Supported formats
Common image formats with export options provided by the tool.
Save time
Get a clean, ready-to-use result in seconds without installing software or configuring a complex workflow.
Guide
How to use this tool
- 1
Set the ratio
Enter a reference width and height, or choose a common format.
- 2
Enter a target dimension
Provide the new width or height you need.
- 3
Get proportional dimensions
The tool instantly calculates the other dimension while preserving the exact ratio.
Tips and best practices
- Use 16:9 for most widescreen videos and displays.
- The 1:1 format is useful for square visuals and some social posts.
- Results are rounded to the nearest whole pixel.
Frequently asked questions
What does an aspect ratio represent?
It describes the proportion of a rectangle. Preserving it prevents an image or video from being stretched or squashed.
Can I use custom reference dimensions?
Yes. Any positive width and height can define a custom ratio.
Does the calculator modify my image?
No. It only calculates dimensions and never uploads or transforms a file.
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