border-radius

The border-radius CSS 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.

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.

Note: As with any shorthand property, individual sub-properties cannot inherit, such as in border-radius:0 0 inherit inherit, which would partially override existing definitions. Instead, the individual longhand properties have to be used.

Constituent properties

This property is a shorthand for the following CSS properties:

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: 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;

/* ... 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;

/* ... 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;

Formal definition

Initial value	as each of the properties of the shorthand: `border-top-left-radius`: `0` `border-top-right-radius`: `0` `border-bottom-right-radius`: `0` `border-bottom-left-radius`: `0`
Applies to	all elements; but User Agents are not required to apply to `table` and `inline-table` elements when `border-collapse` is `collapse`. The behavior on internal table elements is undefined for the moment.. It also applies to `::first-letter`.
Inherited	no
Percentages	refer to the corresponding dimension of the border box
Computed value	as each of the properties of the shorthand: `border-bottom-left-radius`: two absolute `<length>`s or `<percentage>`s `border-bottom-right-radius`: two absolute `<length>`s or `<percentage>`s `border-top-left-radius`: two absolute `<length>`s or `<percentage>`s `border-top-right-radius`: two absolute `<length>`s or `<percentage>`s
Animation type	as each of the properties of the shorthand: `border-top-left-radius`: a length, percentage or calc(); `border-top-right-radius`: a length, percentage or calc(); `border-bottom-right-radius`: a length, percentage or calc(); `border-bottom-left-radius`: a length, percentage or calc();

Formal syntax

<length-percentage>{1,4} [ / <length-percentage>{1,4} ]?where 
<length-percentage> = <length> | <percentage>

Examples

  <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: 80px;
}

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;
}

Live Samples

Sample 1 : https://jsfiddle.net/Tripad/qnGKj/2/
Sample 2 : https://jsfiddle.net/Tripad/qnGKj/3/
Sample 3 : https://jsfiddle.net/Tripad/qnGKj/4/
Sample 4 : https://jsfiddle.net/Tripad/qnGKj/5/
Sample 5 : https://jsfiddle.net/Tripad/qnGKj/6/

Specifications

Specification
CSS Backgrounds and Borders Module Level 4 # border-radius

Browser compatibility

BCD tables only load in the browser