Geometry tools

Image Crop Calculator

Find the largest exact whole-pixel crop for a chosen ratio, including centered crop coordinates and the image area retained.

Your dimensions

On your device

The full image before cropping.

This tool keeps the current image orientation.

Enter an integer ratio, such as 4 and 5.

4:5 is portrait; 5:4 is landscape.

Use a decimal point, without commas. Physical lengths and PPI accept up to 4 decimal places.

Example result

1,600 × 2,000 pixels

Exact 4:5 crop · centered within 3,000 × 2,000 px

Image retained
53.33%
Top-left coordinate
x 700, y 0
Image removed
46.67%
Original imageRetained crop · proportions only
Illustrative geometry · proportions, not actual screen size

Coordinates start at the upper-left of the original image; x increases rightward and y downward.

This is the largest whole-pixel rectangle with the exact selected ratio. It does not create or download a cropped image.

Calculation details & inputs
Inputs used for this result
Image width3000 px
Image height2000 px
Target ratio width4
Target ratio height5
Result details · 6 decimals or 3 significant digits for tiny values
Crop width (px)1,600
Crop height (px)2,000
Left crop origin x (px)700
Top crop origin y (px)0
Removed from right (px)700
Removed from bottom (px)0
Image retained (%)53.333333
Image removed (%)46.666667

Behind the numbers

How the calculation works

Reduce the ratio to a:b. The largest integer scale is floor(min(image width ÷ a, image height ÷ b)).

An exact integer ratio may discard an extra row or column compared with a fractional crop. If centering leaves an odd pixel, the extra pixel is removed from the right or bottom.

Results use the numbers you enter. See the methodology for precision, accepted ranges and sharing behavior.

Useful answers

Common questions

Why can an exact crop remove an extra pixel?

An exact whole-pixel ratio requires both dimensions to be integer multiples of its reduced ratio. The largest such rectangle can be slightly smaller than a crop tool that allows fractional boundaries.

Can I move the crop or download a cropped image?

This tool plans a centered crop and reports its coordinates. It does not edit the file. Use these dimensions in your image editor, then position the crop to preserve the subject.

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