`border-radius` CSS property

The border-radius CSS shorthand property rounds the corners of an element's outer border edge. You can set a single radius to make circular corners, or two radii to make elliptical corners.

Try it

border-radius: 30px;

border-radius: 25% 10%;

border-radius: 10% 30% 50% 70%;

border-radius: 10% / 50%;

border-radius: 10px 100px / 120px;

border-radius: 50% 20% / 10% 40%;

<section class="default-example" id="default-example">
  <div class="transition-all" id="example-element">
    This is a box with rounded corners.
  </div>
</section>

#example-element {
  width: 80%;
  height: 80%;
  display: flex;
  justify-content: center;
  flex-direction: column;
  background-color: #5b6dcd;
  color: white;
  padding: 10px;
}

Constituent properties

This property is a shorthand for the following CSS properties:

• border-top-left-radius
• border-top-right-radius
• border-bottom-right-radius
• border-bottom-left-radius

Syntax

/* The syntax of the first radius allows one to four values */
/* Radius is set for all 4 sides */
border-radius: 10px;

/* top-left-and-bottom-right | top-right-and-bottom-left */
border-radius: 10px 5%;

/* top-left | top-right-and-bottom-left | bottom-right */
border-radius: 2px 4px 2px;

/* top-left | top-right | bottom-right | bottom-left */
border-radius: 1px 0 3px 4px;

/* The syntax of the second radius allows one to four values */
/* (first radius values) / radius */
border-radius: 10px / 20px;

/* (first radius values) / top-left-and-bottom-right | top-right-and-bottom-left */
border-radius: 10px 5% / 20px 30px;

/* (first radius values) / top-left | top-right-and-bottom-left | bottom-right */
border-radius: 10px 5px 2em / 20px 25px 30%;

/* (first radius values) / top-left | top-right | bottom-right | bottom-left */
border-radius: 10px 5% / 20px 25em 30px 35em;

/* Global values */
border-radius: inherit;
border-radius: initial;
border-radius: revert;
border-radius: revert-layer;
border-radius: unset;

The border-radius property is specified as:

• one, two, three, or four <length> or <percentage> values. This is used to set a single radius for the corners.
• followed optionally by "/" and one, two, three, or four <length> or <percentage> values. This is used to set an additional radius, so you can have elliptical corners.

Values

radius		Is a <length> or a <percentage> denoting a radius to use for the border in each corner of the border. It is used only in the one-value syntax.
top-left-and-bottom-right		Is a <length> or a <percentage> denoting a radius to use for the border in the top-left and bottom-right corners of the element's box. It is used only in the two-value syntax.
top-right-and-bottom-left		Is a <length> or a <percentage> denoting a radius to use for the border in the top-right and bottom-left corners of the element's box. It is used only in the two- and three-value syntaxes.
top-left		Is a <length> or a <percentage> denoting a radius to use for the border in the top-left corner of the element's box. It is used only in the three- and four-value syntaxes.
top-right		Is a <length> or a <percentage> denoting a radius to use for the border in the top-right corner of the element's box. It is used only in the four-value syntax.
bottom-right		Is a <length> or a <percentage> denoting a radius to use for the border in the bottom-right corner of the element's box. It is used only in the three- and four-value syntaxes.
bottom-left		Is a <length> or a <percentage> denoting a radius to use for the border in the bottom-left corner of the element's box. It is used only in the four-value syntax.

<length>

Denotes the size of the circle radius, or the semi-major and semi-minor axes of the ellipse, using length values. Negative values are invalid.

<percentage>

Denotes the size of the circle radius, or the semi-major and semi-minor axes of the ellipse, using percentage values. Percentages for the horizontal axis refer to the width of the box; percentages for the vertical axis refer to the height of the box. Negative values are invalid.

For example:

border-radius: 1em / 5em;

/* It is equivalent to: */
border-top-left-radius: 1em 5em;
border-top-right-radius: 1em 5em;
border-bottom-right-radius: 1em 5em;
border-bottom-left-radius: 1em 5em;

border-radius: 4px 3px 6px / 2px 4px;

/* It is equivalent to: */
border-top-left-radius: 4px 2px;
border-top-right-radius: 3px 4px;
border-bottom-right-radius: 6px 2px;
border-bottom-left-radius: 3px 4px;

Description

The radius applies to the whole background, even if the element has no border; the exact position of the clipping is defined by the background-clip property.

The border-radius property does not apply to table elements when border-collapse is collapse.

Formal definition

Formal syntax

border-radius = 
  <length-percentage [0,∞]>{1,4} [ / <length-percentage [0,∞]>{1,4} ]?

<length-percentage> = 
  <length> |
  <percentage>

Examples

Comparing border styles

The following example has seven <pre> elements, each of which demonstrates combinations of border and border-radius styles. The styles applied to each <pre> element are included as the element's contents, so you can see the CSS declarations necessary to create the associated border style:

<pre id="example-1">
  border: solid 10px;
  border-radius: 10px 40px 40px 10px;
</pre>

<pre id="example-2">
  border: groove 1em red;
  border-radius: 2em;
</pre>

<pre id="example-3">
  background: gold;
  border: ridge gold;
  border-radius: 13em / 3em;
</pre>

<pre id="example-4">
  border: none;
  border-radius: 40px 10px;
  background: gold;
</pre>

<pre id="example-5">
  border: none;
  border-radius: 50%;
  background: burlywood;
</pre>

<pre id="example-6">
  border: dotted;
  border-width: 10px 4px;
  border-radius: 10px 40px;
</pre>

<pre id="example-7">
  border: dashed;
  border-width: 2px 4px;
  border-radius: 40px;
</pre>

pre {
  margin: 20px;
  padding: 20px;
  width: 80%;
  height: 50px;
}

pre#example-1 {
  border: solid 10px;
  border-radius: 10px 40px 40px 10px;
}

pre#example-2 {
  border: groove 1em red;
  border-radius: 2em;
}

pre#example-3 {
  background: gold;
  border: ridge gold;
  border-radius: 13em / 3em;
}

pre#example-4 {
  border: none;
  border-radius: 40px 10px;
  background: gold;
}

pre#example-5 {
  border: none;
  border-radius: 50%;
  background: burlywood;
}

pre#example-6 {
  border: dotted;
  border-width: 10px 4px;
  border-radius: 10px 40px;
}

pre#example-7 {
  border: dashed;
  border-width: 2px 4px;
  border-radius: 40px;
}

Using corner-shape with border-radius

When a non-0 border-radius value is applied to a box corner, you can use the corner-shape property (or one of its longhands and shorthands) to apply custom shapes to that corner, such as a bevel, notch, or squircle. This example demonstrates corner-shape usage.

HTML

The markup for this example contains a single <div> element.

<div></div>

CSS

We give the box some basic styles, which we've hidden for brevity. We also apply a box-shadow, a border-radius of 0 20% 50px 30%, and a corner-shape of superellipse(0.5) bevel notch squircle.

body {
  font-family: "Helvetica", "Arial", sans-serif;
  width: 240px;
  margin: 20px auto;
}

div {
  width: 100%;
  height: 180px;
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: green;
  background-image: linear-gradient(
    to bottom,
    rgb(255 255 255 / 0),
    rgb(255 255 255 / 0.5)
  );
}

div {
  box-shadow: 1px 1px 3px gray;
  border-radius: 0 20% 50px 30%;
  corner-shape: superellipse(0.5) bevel notch squircle;
}

Result

The rendered result looks like this:

Note how no corner shape is applied to the top-left corner, because it has a border-radius of 0 set.

Specifications

Browser compatibility

See also

• Border-radius-related CSS properties: border-top-left-radius, border-top-right-radius, border-bottom-right-radius, border-bottom-left-radius, border-start-start-radius, border-start-end-radius, border-end-start-radius, border-end-end-radius