Aspect Ratio Calculator

Reduce any width and height pair, widen or narrow it to a target, and get the multiplier, the pad or crop needed for a fixed canvas.

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Reduce a width and height to their lowest-term ratio by greatest common divisor, list the standard resolutions that share it, and solve the scale needed to fit a source size inside a given box.

GCD REDUCTION RESOLUTION MATCHES SCALE TO FIT

Enter a pixel size and it is reduced by its greatest common divisor, so 1920×1080 becomes 16:9 because the gcd is 120 — not by dividing by hand until something looks tidy. The matches list compares the reduced pair, which is why 854×480 does not appear under 16:9: it reduces to 427:240.

Width

Height

Scale W×H to fit inside

Allow upscaling above 1

The reduced ratio

Numbers

Resolutions with this ratio

Scale to fit

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