<!DOCTYPE html>
<html>
<head>
    <title>size of box zoom test</title>
    <style>
        body {
            background: silver;
        }
        #container {
            background: white;
            width: 500px;
            height: 50px;
        }
        #ruler > div {
            float: left;
            width: 49px;
            border-right: 1px solid black;
            text-align: right;
            height: 50px;
        }
        #test {
            clear: left;
            position: absolute;
            top: 30px;
        }
        #test > div {
            clear: left;
        }
        #test > div > div {
            float: left;
            width: 500px;
            height: 10px;
            background: navy;
        }
        #console {
            clear: left;
        }
    </style>
</head>
<body>
    <div id="container">
        <div id="ruler"></div>
        <div id="test"><div></div></div>
    </div>
</body>
<script>
    var testContainer = document.getElementById('test');
    var rulerElement = document.getElementById('ruler');

    function init()
    {
        rulerElement.innerHTML = '';
        for (var i = 0; i < 10; i++) {
            rulerElement.appendChild(document.createElement('div'));
            rulerElement.lastChild.appendChild(document.createTextNode(50 + i * 50));
        }
    }

    function test(zoom)
    {
        var testElement = document.createElement('div');
        testElement.style.zoom = zoom + '%';
        testElement.appendChild(document.createElement('div'));
        testContainer.appendChild(testElement);
    }

    init();
    test(100);
    test(65);
    test(30);

</script>
</html>