Image & Video Aspect-Ratio Calculator
See the largest centred crop for a vertical, square or widescreen frame before resizing your image or video.
Free · No login · Browser-local · No automatic saving
Enter your details
Use your own values or load an example. Nothing here is sent to an AI model or saved to an account.
Results appear here after you calculate. Editing an input clears the previous result.
How the calculation works
Fit unit = smaller of source width ÷ target ratio width and source height ÷ target ratio height. Crop dimensions = fit unit × target ratio. Each edge loses half the difference between source and crop dimensions. Calculations use fractional pixels; round in your editor and check the final ratio. This does not upload, crop or generate a file.
Worked example
A 1920 × 1080 landscape image cropped to a square keeps 1080 × 1080 pixels: remove 420 pixels from each side. Keep faces and captions inside the retained area.
Method version 1.0.0. This planning tool does not fetch provider rates or send your inputs to a server.
Common questions
Does a centred crop preserve the subject?
Not necessarily. Reposition the crop in your editor if the subject is near an edge. The preview shows geometry, not the contents of your file.
Does this resize my image?
No file is uploaded. This tool calculates dimensions; use an image or video editor to make and inspect the final crop.