When we use jQuery to retrieve the CSS values such as width and height, the unit px is included.
For example, if you have a div which is 100px wide.
<div id="eureka" style="width: 100px;"></div>
Call .css() to get the width value.
$('#eureka').css('width'); // Return '100px'
But most of the time we would like to have a numeric value rather than a string. Here comes the numeric solution.
parseFloat($('#eureka').css('width')); // Return 100
You don’t need to worry about the unit em. This is because .css() must return the value in unit px.