Aspect Ratio Calculator
Enter original width and height to get the simplified aspect ratio, decimal ratio, and matching width or height for a target size.
Runs locally in your browser. This tool does not upload your input.
Inputs
Results
- Aspect ratio
- 16:9
- Decimal
- 1.7778
- Width from height
- 1280
- Height from width
- 720
Keep the same proportion when resizing images, videos, or layouts.
How to calculate aspect ratio
Find a simplified width-to-height ratio and calculate matching dimensions for images, videos, and layouts.
How to use it
- Enter the original width and height.
- Enter a target width to calculate the matching height.
- Enter a target height to calculate the matching width.
Why aspect ratio matters
Aspect ratio keeps visual content from stretching. A 1920 by 1080 image simplifies to 16:9, so any resized version should keep that same relationship.
Common uses
- Preparing images for social posts, thumbnails, or banners.
- Resizing videos without distortion.
- Checking layout proportions before exporting assets.
Local calculation
Only the dimensions you type are used locally in the browser.
Aspect ratio calculator FAQ
- What does 16:9 mean?
- It means the width has 16 parts for every 9 parts of height.
- Does this resize an image file?
- No. It calculates proportional dimensions. Use the Image Resizer when you need to process an actual file.
- Can I use decimals?
- The interface is intended for pixel dimensions, so whole numbers are the most useful input.