Find the simplest ratio of a width and height, or scale a ratio to a new size. Nothing leaves your browser.
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The ratio is width and height divided by their greatest common divisor. Resizing multiplies the known side by the other side of the ratio and divides by its own. Everything runs in your browser.
Divide width and height by their greatest common divisor. 1920×1080 has a divisor of 120, so the ratio is 16:9.
Enter the ratio, then fill in either the new width or the new height. The other side is calculated for you. For 16:9 at 1280 wide, the height is 720.
16:9 for most video and monitors, 4:3 for older screens, 3:2 for many photos, 1:1 for square posts and 9:16 for vertical video.
Scaling a ratio to a size does not always give a whole number. The tool rounds to two decimals; round to whole pixels yourself for images.
Free tool, provided as is, with no guarantee. Results are for general information. Please do not enter personal information in feedback.