files/en-us/web/svg/reference/attribute/r/index.md
The r attribute defines the radius of a circle.
You can use this attribute with the following SVG elements:
Percentages refer to the normalized diagonal of the current SVG viewport, which is calculated as <math><mfrac><msqrt><mrow><msup><mi><width></mi><mn>2</mn></msup><mo>+</mo><msup><mi><height></mi><mn>2</mn></msup></mrow></msqrt><msqrt><mn>2</mn></msqrt></mfrac></math>.
html,
body,
svg {
height: 100%;
}
<svg viewBox="0 0 300 200" xmlns="http://www.w3.org/2000/svg">
<radialGradient r="0" id="myGradient000">
<stop offset="0" stop-color="white" />
<stop offset="100%" stop-color="black" />
</radialGradient>
<radialGradient r="50%" id="myGradient050">
<stop offset="0" stop-color="white" />
<stop offset="100%" stop-color="black" />
</radialGradient>
<radialGradient r="100%" id="myGradient100">
<stop offset="0" stop-color="white" />
<stop offset="100%" stop-color="black" />
</radialGradient>
<circle cx="50" cy="50" r="0" />
<circle cx="150" cy="50" r="25" />
<circle cx="250" cy="50" r="50" />
<rect x="20" y="120" width="60" height="60" fill="url(#myGradient000)" />
<rect x="120" y="120" width="60" height="60" fill="url(#myGradient050)" />
<rect x="220" y="120" width="60" height="60" fill="url(#myGradient100)" />
</svg>
{{EmbedLiveSample("Example", '100%', 200)}}
For {{SVGElement('circle')}}, r defines the radius of the circle and therefore its size. With a value lower or equal to zero the circle won't be drawn at all.
[!NOTE] The radius size of a
<circle>can also be defined with the {{cssxref("r")}} geometry property.
For {{ SVGElement("radialGradient") }}, r defines the radius of the end circle for the radial gradient.
The gradient will be drawn such that the 100% gradient stop is mapped to the perimeter of this end circle. A value of lower or equal to zero will cause the area to be painted as a single color using the color and opacity of the last gradient {{ SVGElement("stop") }}.
<table class="properties"> <tbody> <tr> <th scope="row">Value</th> <td> <strong ><a href="/en-US/docs/Web/SVG/Guides/Content_type#length" ><length></a ></strong > </td> </tr> <tr> <th scope="row">Default value</th> <td><code>50%</code></td> </tr> <tr> <th scope="row">Animatable</th> <td>Yes</td> </tr> </tbody> </table>{{Specifications}}
{{Compat}}