<svg width="300" height="200"
  xmlns="http://www.w3.org/2000/svg"
  xmlns:html="http://www.w3.org/1999/xhtml">
  <title>Ellipse coordinates and radii specified using calc</title>
  <html:link rel="help" href="https://svgwg.org/svg2-draft/geometry.html"/>
  <html:link rel="match"  href="ellipse-ref.svg" />
  <style>
    ellipse {
      fill: blue;
      font-size: 40px;
    }
  </style>
  <ellipse cx="calc(80px + 25% - 2em)" cy="calc(80px + 60% - 2em)"
    rx="calc(4 * 5%)" ry="calc(5 * 5%)" />
</svg>