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                <div class="box">
  <div class="wrapper"><a class="target" href="#">Target</a></div>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Numquam, perferendis. Incidunt deserunt temporibus, tempore et, possimus fuga quod dolore, excepturi quia magnam quidem. Nobis, dolores dignissimos 
<div class="log-a">浏览器计算的尺寸:</div>
<div class="log-b">用getBoundingClientRect()获取的尺寸:</div>


                .box {
  width: 200px;
  height: 200px;
  border: 1px solid #ccc;
  background: #eee; 
  margin-bottom: 20px;
.target {
  float: left; 
  width: 50px;
  height: 50px;
  line-height: 50px;
  font-size: 12px;
  text-align: center;
  transform-origin: 0 center;
  transform: scale(.7) translateX(40px);
  background: #333;
  color: #fff;
.wrapper {


  // get the actual size  
  var calculatedRect = $('.target')[0].getBoundingClientRect();
  $('.log-a').append('width:' + $('.target').width() + ',height:' + $('.target').height());
  $('.log-b').append('width:' + calculatedRect.width + ',height:' + calculatedRect.height);