How can I make DIV 100% height of browser without vertical scrolling of header

Question

Both the left and right panels have a height of 100%, but since the Header div takes up X amount of space, there is some vertical scrolling in the window th

Answer 1

You can use absolute positioning if you want to have it 100% height always. And then use scroll bars if required inside the leftpanel or the rightpanel.

Example: http://jsfiddle.net/G7unG/2/

html, body{
    height: 100%;
    margin: 0;
}
.header{
    background: #333;
    padding: 15px;
    text-align:center;
    font-size: 18px;
    font-family: sans-serif;
    color: #FFF;
    height: 22px;
}
.leftpanel, .rightpanel{
    top: 52px;
    bottom: 0;
    position: absolute;
}
.leftpanel{
    width: 70%;
    left: 0;
    background: #CCC;
}
.rightpanel{
    width: 30%;
    right: 0;
    background: #666;
}

Solution 2 - use fixed percentages for height: http://jsfiddle.net/G7unG/4/

html, body{
    height: 100%;
    margin: 0;
}
.header{
    background: #333;
    padding: 15px;
    text-align:center;
    font-size: 18px;
    font-family: sans-serif;
    color: #FFF;
    height: 30%;
    box-sizing: border-box;
}
.leftpanel, .rightpanel{
    height: 70%;
    float: left;
}
.leftpanel{
    width: 70%;
    left: 0;
    background: #CCC;
}
.rightpanel{
    width: 30%;
    float: right;
    background: #666;
}