CSS | block-size Property

Last Updated : 28 Jun, 2022

The block-size property in CSS is used to define the horizontal or vertical size of an element's block. It coincides with the width or the height property, depending on the value of the writing-mode property. it leaves the space below are left of the element text.
Syntax:

block-size: length|percentage|auto|inherit|initial|unset

Property values:

length: It sets a fixed value defined in px, cm, pt etc. Negative values are allowed. Its default value is 0px.
percentage: It is same as length but it sets in terms of percentage of the window size.
auto: It is used when it is desired that the browser determines the block-size.
initial: It is used to set the value of the block-size property to its default value.
inherit: It is used when it is desired that the element inherit theblock-size property of its parent as its own.
unset: It is used unset the default block-size.

Below examples illustrate the block-size property in CSS:
Example 1:

html

<!DOCTYPE html>
<html>

<head>
    <title>CSS | block-size Property</title>
    <style>
        h1 {
            color: green;
        }
        
        .geek {
            background-color: yellow;
            block-size: 40%;
            writing-mode: vertical-rl;
        }
    </style>
</head>

<body>
    <center>
        <h1>Geeksforgeeks</h1>
        <b>CSS | block-size Property</b>
        <br><br>
        <div>
            <b class="geek">GeeksforGeeks</b>
        </div>
    </center>
</body>

</html>

Output:

Example 2:

html

<!DOCTYPE html>
<html>

<head>
    <title>CSS | block-size Property</title>
    <style>
        h1 {
            color: green;
        }
        
        p.geek { 
                width: 200px; 
                height: 200px; 
                border: 1px solid black; 
                writing-mode: horizontal-tb; 
                color: white; 
                background: green; 
                block-size: 250px;

            } 
    </style>
</head>

<body>
    <center>
        <h1>Geeksforgeeks</h1>
        <b>CSS | block-size Property</b>
        <br><br>
        <div>
            <p class="geek">GeeksforGeeks</p>


        </div>
    </center>
</body>

</html>