Aspect Ratio Crop Retention Calculator

Method, formula and assumptions

Keep the limiting dimension and floor the other to whole pixels using target width/height ratio. Retained fraction = crop pixel area/source area. Removed pixels are totals across both edges, not per edge.

Input definitions and supported units

• Source width (pixels): Whole-number count, from 1 to 1000000; must be positive.
• Source height (pixels): Whole-number count, from 1 to 1000000; must be positive.
• Target ratio width: Measured or assumed numerical value, from 0.001 to 1000; must be positive.
• Target ratio height: Measured or assumed numerical value, from 0.001 to 1000; must be positive.

Worked example with answer

A 6,000 x 4,000 image cropped to 16:9 retains 6,000 x 3,375 pixels, or 84.375%. It removes zero horizontal and 625 total vertical pixels.

How to use the results

This reports pixel retention and framing loss, not print dimensions or PPI. Odd removals require asymmetric one-pixel edge allocation.

Results retain full precision internally and display up to four decimal places. Very small nonzero results use scientific notation rather than appearing as zero. Check the labels before comparing values across units.

Limitations and references

Whole-pixel rounding can slightly deviate from the exact ratio. Composition, stabilization margins, optical quality and output resizing are excluded.

The method is a self-contained arithmetic, geometric or explicitly stated mathematical model. There are no imported tariffs, empirical presets or equipment specifications; measured values and allowances must come from your own process.

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