jQuery .height() gets or sets height of the target element;
jQuery .innerHeight() gets the computed height (including padding but not border) of the target element;
jQuery .outerHeight() gets the computed height (including padding and border) of the target element;
Also check jQuery .width()

js:

$(function(){
    var target_height = $('.target').height(); // get target height
    $('.target2').height( target_height ); // set target height
    $('.target2 .height2 span').text( target_height );
    $('.height_log span').text( $('.target').height() );
    $('.innerHeight_log span').text( $('.target').innerHeight() );
    $('.outerHeight_log span').text( $('.target').outerHeight() );
    
    $('.windowHeight_log span').text( $(window).height() ); // returns height of browser viewport
    $('.documentHeight_log span').text( $(document).height() ); // returns height of HTML document
});​

html:

<div class="well target">
    <span class="label label-warning">.target</span>
    <p>set in css:
        <span class="label label-info">height: 100px;</span>
        <span class="label label-info">padding: 10px;</span>
        <span class="label label-info">margin: 12px;</span>
        <span class="label label-info">border: 2px;</span>
    </p>
</div>

<div class="well">
    <p>get .target properties with jQuery:
    
        <span class="label label-success height_log">
            .target height: <span></span>
        </span>&nbsp;
        
        <span class="label label-success innerHeight_log">
            .target innerHeight: <span></span>
        </span>&nbsp;
        
        <span class="label label-success outerHeight_log">
            .target outerHeight: <span></span>
        </span>&nbsp;
    </p>
    
    <p>
        <span class="label label-success windowHeight_log">
            window height: <span></span>
        </span>&nbsp;
        
        <span class="label label-success documentHeight_log">
            document height: <span></span>
        </span>&nbsp;
    </p>
    
</div>

<div class="target2">
    <span class="label label-success height2">height:<span></span></span>
    <span>height of this block set by jQuery (same as .target block)</span>
</div>

css:

.target {
    height: 100px;
    padding: 10px;
    margin: 12px;
    border: 2px solid #bbb;
}

.target2 {
    background: #ccc;
    margin: 10px 0;
}