Aspect ratio notes
The checker reads the pixel width and height of a local image, then reduces the numbers to the simplest ratio.
It is useful before resizing because it tells you which dimension should change when you want to keep the same shape.
Image Aspect Ratio Calculator
Upload an image or enter dimensions to find its simplified ratio, orientation, megapixels and proportional resize values before resizing or publishing.
Upload or type dimensionsSimplified ratioProportional resize mathNo upload
Aspect ratio checker
Result preview
Choose an image or enter dimensions to see results.
Choose an image or enter dimensions to see results.
How it works
- 1Choose an image or type the width and height.
- 2Review the simplified aspect ratio, decimal ratio, orientation and megapixels.
- 3Enter a new width or height to calculate the matching dimension before resizing.
Privacy and limits
- Images are read in the browser and are not uploaded.
- This tool calculates ratio and dimensions; it does not crop the image.
- Social platforms and printers may still crop or fit images differently.
Common use cases
- Check whether an image is 16:9, 4:3, 1:1 or another ratio
- Calculate a matching height for a fixed width
- Compare a source image with a social or print target
Calculation notes
- Ratio is calculated from pixel dimensions, not visual subject placement.
- Megapixels are width x height divided by one million.
- This tool does not crop or pad the file.
Original test sample
- Upload or enter 1920 x 1080 and confirm the simplified ratio is 16:9.
- Enter a target width of 1200 for a 4:3 image and confirm the matching height is 900.
Frequently asked questions
Are my images uploaded?
No. ImgShrink processes selected images in your browser and does not upload them to a server.
Does resizing crop my image?
The default resize workflow fits the image into the selected dimensions. Empty space may be filled when an exact canvas is needed.
Why is an output format unavailable or different?
The browser controls image decoding and export support. Some browsers may not export AVIF or may flatten unsupported transparency.
Source and compatibility notes
This tool works in the browser, so output support depends on what your browser can read and export.
Last checked: 2026-09-07
Notes
- No server-side image processing is used.
- Output format support depends on the browser.
- Animated images and metadata are not treated as guaranteed preserved data.
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