jquery css values in ems rathen than px?

can i get an elements css distance values in ems rather than px?

    #pointer{
        height:1em;
        b开发者_Go百科order:1px solid black;
        width:1em;
        position:relative;
        top:15em;
    }

top = $('#pointer').css('top');

>> top = 15

Thanks :)

You can use this jquery plugin :)