How to Create Boxes with Rounded Corners in CSS

Prior to browser support for CSS3, creating boxes with rounded corners required the creative use of background images, borders, and positioning. Thankfully, these days are gone. Today, browsers support CSS3 and its border-radius properties. The border-radius properties makes rounding the corners on a box easy.

  1. Start with an HTML page containing two boxes.
    <meta charset="UTF-8">
    <link rel="stylesheet" type="text/css" href="../reset-meyer.css">
    <style type="text/css">
    body {
    	font-family:"Trebuchet MS", Arial, Helvetica, sans-serif
    #box1, #box2{
    #box1 {
    #box2 {
    h2, p  {
    #box1 p, #box2 p {
    <title>Rounded Corner Boxes</title>
    <div id="box1">
    	<h2>Example 1</h2>
    <div id="box2">
    	<h2>Example 2</h2>
    If you open this page in a browser, it looks like this:
    sharp corner boxes
  3. The border-radius properties work by curving the corner according to a circle with its center offset from the corner of the box by the distance you specify. To create a simple box with rounded corners, add the border-radius property to box1.
    #box1 {
    	background: #c00;
    	border-radius: 25px;
    The border-radius property is a shorthand property that sets the radius for all four corners of the box to the same value when given only one value.
  4. To change the roundness of the corners to different values, you can set more than one value, with the values separated by spaces. The first value represets the top left corner, the second value represents the top right corner, the third value represents the bottom right corner, and the fourth value represents the bottom left corner. Add the following border-radius to box2.
    #box 2 {
    	background: #ff0;
    	border-radius: 10px 140px 30px 140px;
  5. Open the HTML page in a browser. The two boxes should look like this:
    rounded corners
Author: Chris Minnick

Chris Minnick, the co-founder of WatzThis?, has overseen the development of hundreds of web and mobile projects for customers from small businesses to some of the world’s largest companies. A prolific writer, Chris has authored and co-authored books and articles on a wide range of Internet-related topics including HTML, CSS, mobile apps, e-commerce, e-business, Web design, XML, and application servers. His published books include Adventures in Coding, JavaScript For Kids For Dummies, Writing Computer Code, Coding with JavaScript For Dummies, Beginning HTML5 and CSS3 For Dummies, Webkit For Dummies, CIW E-Commerce Designer Certification Bible, and XHTML.

About Webucator

Webucator provides instructor-led training to students throughout the US and Canada. We have trained over 90,000 students from over 16,000 organizations on technologies such as Microsoft ASP.NET, Microsoft Office, Azure, Windows, Java, Adobe, Python, SQL, JavaScript, Angular and much more. Check out our complete course catalog.