Try it Editor: With the CSS3 box-sizing Property

Edit This Code :


<!DOCTYPE html>
<html>
<head>
<style> 
.div1 {
    width: 300px;
    height: 100px;
    border: 1px solid blue;
    box-sizing: border-box;
}

.div2 {
    width: 300px;
    height: 100px;    
    padding: 50px;
    border: 1px solid red;
    box-sizing: border-box;
}
</style>
</head>
<body>

<div class="div1">Both divs are the same size now!</div>
<br>
<div class="div2">Hooray!</div>

</body>
</html>

Result :