Resize and maintain the golden ratio (3:5)?

[eluser]TheFuzzy0ne[/eluser]
The longest dimension should be used as your master dimension.

If the height is the largest dimension:

Code:

function getWidth($height)
{
    return ($height / 3) * 5
}

If the width is the largest dimension:

Code:

function getHeight($width)
{
    return ($width / 5) * 3
}

Just bear in mind that the further the image is away from this ratio, the more image you'll lose when it's cropped.