CSS3 Height property is used to specify the height of an HTML element. The height of the HTML elements does not include border, margin, padding, etc. So, by default, the CSS3 Height property defines the height of the content area.
We can change the Height of an HTML Element by using the CSS width property.
We normally use px, vh, and % unit for height property.
{height : 10px;}
property value
<!DOCTYPE html>
<html>
<head>
<style>
.tdb-height{
width:200px;
height:300px;
background-color:black;
color:white;
padding:10px;}
</style>
</head>
<body>
<p class="tdb-height">css height property</p>
</body>
</html>
If you are working on a responsive layout then set the default value of height.