Aspect Ratio Calculator

An aspect ratio describes width relative to height. Enter dimensions such as 1920 × 1080 and verify that the ratio is reduced consistently, then lock the ratio and change only one dimension. The other dimension should update using the same ratio, with rounding made visible for pixel sizes that cannot be exact integers.

Check zero or negative dimensions, portrait orientation, and switching between pixel and physical dimensions if available. Cropping and letterboxing are different from proportional resizing; the tool should not silently confuse them. Report original width and height, desired output, rounding rule, and the displayed result.