Here my example. Supper simple
$(document).ready(function() {_x000D_
_x000D_
var textarea = $("#my_textarea");_x000D_
_x000D_
textarea.keydown(function(event) {_x000D_
_x000D_
var numbOfchars = textarea.val();_x000D_
var len = numbOfchars.length;_x000D_
$(".chars-counter").text(len);_x000D_
_x000D_
});_x000D_
_x000D_
_x000D_
});
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>_x000D_
<textarea id="my_textarea" class="uk-textarea" rows="5" name="text"></textarea>_x000D_
<h1 class="chars-counter">0</h1>
_x000D_