r

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 $\frac{\sqrt{{<width>}^{2} + {<height>}^{2}}}{\sqrt{2}}$ .

Example

html,
body,
svg {
  height: 100%;
}

html

<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>

circle

For <circle>, r defines the radius of the circle and therefor its size. With a value lower or equal to zero the circle won't be drawn at all.

Value	<length> \| <percentage>
Default value	`0`
Animatable	Yes

Note: The radius size of a <circle> can also be defined with the r geometry property.

radialGradient

For <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 <stop>.

Value	<length> \| <percentage>
Default value	`50%`
Animatable	Yes

Specifications

Specification
Scalable Vector Graphics (SVG) 2 # R
Scalable Vector Graphics (SVG) 2 # RadialGradientElementRAttribute