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.

Done =)

Reference: