contenteditable div 2 , overflow:auto; display-table;, :
DEMO
HTML:
<div class="container1">
<div class="container2">
<div contenteditable="true" class="textarea"></div>
</div>
</div>
CSS:
.container1{
height:60px;
width:273px;
overflow:auto;
border:1px solid green;
}
.container2 {
min-height:100%;
display:table;
}
.textarea {
width:273px;
font-size: 18px;
font-weight: normal;
line-height: 18px;
outline: none;
text-align: center;
vertical-align: middle;
display: table-cell;
position: relative;
-webkit-user-select: text;
-moz-user-select: text;
-ms-user-select: text;
user-select: text;
word-wrap: break-word;
overflow:hidden;
}