Aspect ratio calculator

Resize dimensions while keeping the same proportions.

Processed on your device. No file upload.

How to use this tool

  1. Enter your values or try the example.
  2. Run the tool and check the result.
  3. Save the result where a download is available.

Supported features & limits

Enter the original width and height, then a target width. The new height is rounded to a whole pixel. This calculates dimensions; it does not resize an image file.

What happens to my files?

Your browser reads the file locally. File contents are not sent to our server. Closing or resetting this page clears the working result. Downloaded copies remain on your device.

Maintained by Roman Zmazhenko. Updated 1 November 2026.