When to use Resize Image by Percentage
Make an image 50% smaller or 200% larger in one step. Enter a percentage and the new width and height are calculated for you.
The best image settings depend on where the picture will be used. Pixel dimensions describe width and height; file size describes bytes. Changing one does not guarantee a particular value for the other. Keep the original, compare the result at its intended size, and choose a format accepted by the destination.