 <p>I devised a solution that is simple however perhaps not very efficient. For my purposes it works well.</p> <pre><code>SELECT ROUND( ST_Distance_Sphere( ST_Centroid(ST_MinimumBoundingCircle(geom)), ST_PointN(ST_Boundary(ST_MinimumBoundingCircle(geom)), 1) ) / 1000 ) AS radius, ST_AsGeoJSON(ST_Centroid(geom)) AS center FROM "Regions" </code></pre> <p>The result ends up being a radius in km and the centroid.</p>