How aspect ratio calculator works
Scale screen dimensions while preserving their ratio.
Formula and convention
Target height = original height x target width / original width. Reduce width:height with the greatest common divisor.A worked example
1920 by 1080 is 16:9. A width of 800 gives height 450.
Scope and precision
Output rounds to the nearest pixel. This calculates dimensions; it does not resize or upload an image.
Displayed results may be rounded. Inputs are processed locally and are not stored by this site. Keep the original values if you need to reproduce the result.
Why might another tool give a different result?
Compare unit definitions, rounding, period assumptions, and input values. This page states the convention used by this calculator.