Use the JavaScript height() method
You can set the height of a <div> box dynamically using the jQuery height() method.
The height() method simply returns the element's height as unit-less pixel value. However calling the height(value) method sets the height of the element, where the value can be either a string (e.g. 100%, 50px, 25em, auto etc.) or a number. If only a number is provided for the value, jQuery assumes it as a pixel unit. Let's try out an example and see how it works:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>jQuery Set a DIV height</title>
<style>
.box{
background: #f2f2f2;
border: 1px solid #ccc;
}
</style>
<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
<script>
$(document).ready(function(){
$(".set-height-btn").click(function(){
var newHeight = $(".input-height").val();
$(".box").height(newHeight);
});
});
</script>
</head>
<body>
<form>
<input type="text" class="input-height">
<button type="button" class="set-height-btn">Set Height</button>
<p>Enter the value in input box either as number (e.g. 100, 200) or combination of number and unit (e.g. 100%, 200px, 50em, auto) and click the "Set Height" button.</p>
</form>
<br>
<div class="box">This is simple DIV box</div>
</body>
</html>
