How is border-box different from content-box ? Last Updated : 05 Aug, 2025 Comments Improve Suggest changes Like Article Like Report CSS (Cascading Style Sheets) is a stylesheet language used to design a webpage to make it attractive. The reason for using this is to simplify the process of making web pages presentable. It allows you to apply styles on web pages. More importantly, it enables you to do this independent of the HTML that makes up each web page. In this article, we will learn how border-box is different from content-box. prerequisite :- Must Know CSS BOX MODEL border-box and content-box are the two different values of box-sizing. content-box: This is the default value of box-sizing. The dimension of element only includes 'height' and 'width' and does not include 'border' and 'padding' given to element. Padding and Border take space outside the element. Example: <html> <head> <style> .box { width: 300px; height: 200px; padding: 15px; border: 10px solid black; box-sizing: content-box; background: red; display: inline-block; } </style> </head> <body> <h1 class="box">GeeksForGeeks</h1> </body> </html>BOXCSS BOX MODEL Note :- border-box = size of content + padding + border In the above scenario, width = width of content border-box width = width of content + left padding + right padding + left border + right border Syntax: box-sizing: content-box;border-box: In this value, not only width and height properties are included but you will find padding and border inside of the box for example .box {width: 200px; border: 10px solid black;} renders a box that is 200px wide. Example: <html> <head> <style> .box { width: 200px; height: 200px; padding: 15px; border: 10px solid green; box-sizing: border-box; background: red; display: inline-block; } </style> </head> <body> <h1 class="box">Heading 1</h1> </body> </html>BOXCSS BOX MODEL Calculation of dimension width = border + padding + width of the content, height = border + padding + height of the content. Syntax: box-sizing: border-box; Note :- when using box-sizing : content-box; the content size remain same while border-box size grows as padding and border grow. but when using box-sizing: border-box; , the size of border-box remains same while size of content decreases as padding and border grow. Example: In the below example, we will see the difference between the width when content-box and border-box properties are applied. HTML <!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"/> <meta http-equiv="X-UA-Compatible" content="IE=edge"/> <meta name="viewport" content="width=device-width, initial-scale=1.0"/> <title>GeeksForGeeks</title> <style> h1 { color: green; text-align: center; } div { width: 200px; height: 200px; padding: 15px; border: 10px solid black; background: green; display: inline-block; } .content-box { box-sizing: content-box; } .border-box { box-sizing: border-box; } </style> </head> <body> <h1>GeeksForGeeks</h1> <div class="content-box"> <h3>Content Box</h3> </div> <div class="border-box"> <h3>Border Box</h3> </div> </body> </html> Output: content box and border box Comment More infoAdvertise with us Next Article CSS Introduction P pall58183 Follow Improve Article Tags : Web Technologies CSS CSS-Questions Similar Reads CSS Tutorial CSS stands for Cascading Style Sheets. It is a stylesheet language used to style and enhance website presentation. CSS is one of the three main components of a webpage, along with HTML and JavaScript.HTML adds Structure to a web page.JavaScript adds logic to it and CSS makes it visually appealing or 7 min read CSS Introduction CSS (Cascading Style Sheets) is a language designed to simplify the process of making web pages presentable.It allows you to apply styles to HTML documents by prescribing colors, fonts, spacing, and positioning.The main advantages are the separation of content (in HTML) and styling (in CSS) and the 4 min read CSS Syntax CSS is written as a rule set, which consists of a selector and a declaration block. The basic syntax of CSS is as follows:The selector is a targeted HTML element or elements to which we have to apply styling.The Declaration Block or " { } " is a block in which we write our CSS.HTML<html> <h 2 min read CSS Selectors CSS Selectors are used to target HTML elements on your pages, allowing you to apply styles based on their ID, class, type attributes, and more. There are mainly 5 types of selectors.Basic CSS Selectors: These are used to target elements by tag, .class, or # ID for fundamental styling needs.Combinato 7 min read CSS Comments CSS comments are used to add notes or explanations to your code, helping you and others understand it better. They start with /* and end with */ and can be used for both single-line and multi-line comments. Note: Comments are ignored by browsers, so they won’t affect how your webpage looks or works. 2 min read CSS Colors CSS colors are used to set the color of different parts of a webpage, like text, background, and borders. This helps make the page look more attractive and easier to read. You can define colors using names, hex codes, RGB values, and more.You can try different formats of colors here- #content-iframe 5 min read CSS Borders Borders in CSS are used to create a visible outline around an element. They can be customized in terms ofWidth: The thickness of the border.Style: The appearance of the border (solid, dashed, dotted, etc.).Color: The color of the border.You can try different types of borders here- #custom-iframe{ he 5 min read CSS Margins CSS margins are used to create space around an element, separating it from neighboring elements and the edges of the webpage. They control the layout by adjusting the distance between elements, providing better organization and readability.Syntax:body { margin: value;}HTML<html> <head> 4 min read CSS Height and Width Height and Width in CSS are used to set the height and width of boxes. Their values can be set using length, percentage, or auto.Width and HeightThe width and height properties in CSS are used to define the dimensions of an element. The values can be set in various units, such as pixels (px), centim 4 min read CSS Outline CSS outline is a property used to draw a line around an element's border. It does not affect the layout, unlike borders. It's often used to highlight elements, providing a visual emphasis without altering the dimensions of the element.Syntaxselector{ outline: outline-width outline-type outline-color 4 min read Like