css - Jquery not getting the correct screen size -

i don't know problem comes from, did guess in title.

basically, trying

<div id="header">header</div> <div id="content">content</div><!-- max screen height possible --> <div id="footer">footer</div> 

after doing simple calculation such as: window_height - header_height - footer_height, not fitting correctly in screen. (total 3 divs height bigger window)

function adjustbody(){     var windowh = $(window).height();     var headerh = $("#header").height();     var footerh = $("#footer").height();     var contenth = windowh - headerh - footerh;     $("#content").css("min-height",contenth); } 

see full code here. jsfiddle

am missing height substract?

reset body/html margin , padding.

body, html {      margin: 0px;     padding: 0px;  }