Video Aspect Ratio Calculator Online
Use a video aspect ratio calculator online to simplify width and height and calculate matching dimensions without uploading a file.
Aspect ratio
16:9
Calculated resolution
1280 × 720
Common matching resolutions
3840 × 2160
2560 × 1440
1920 × 1080
1280 × 720
854 × 480
640 × 360
Files are processed locally in your browser and are not uploaded.
About this tool
Enter source dimensions to reduce them to a clean ratio, then calculate a new width or height that preserves the same framing. Common width examples make it easier to compare delivery sizes before editing or encoding.
How to use
- Choose a supported local file or enter the required values.
- Review the available settings and run the tool.
- Check the result, then download or copy it before closing the page.
Features
- Simplifies dimensions with the greatest common divisor.
- Calculates a matching width or height.
- Shows common target-width resolutions instantly.
Common use cases
- Find whether footage is 16:9, 9:16, 4:3 or another ratio.
- Calculate a proportional resize before encoding.
- Plan canvas dimensions for a video cover.
Common issues and tips
- Display aspect ratio can differ from stored pixel dimensions in files with non-square pixels.
- Rounded integer dimensions may differ by one pixel from the exact ratio.
Privacy
Your video, image or subtitle data is processed locally in your browser and is not uploaded to Tools12345.
Frequently asked questions
Does it resize my video?
No. It only calculates ratios and target dimensions.
What does 1920 × 1080 simplify to?
It simplifies to 16:9.
Why is the result rounded?
Video dimensions use whole pixels, so fractional results must be rounded.