How can I calculate the visible area of my camera in world space and take zoom into account?

I am trying to get the bounds from an orthographic camera in Unity which take into account the current orthographic size (zoom).

I thought that I could use the cameraToWorldMatrix to transform the camera pixel rectangle into world coordinates.

var m = camera.cameraToWorldMatrix;

var bL = m.MultiplyPoint(new Vector3(camera.pixelRect.xMin, camera.pixelRect.yMin));
var uL = m.MultiplyPoint(new Vector3(camera.pixelRect.xMin, camera.pixelRect.yMax));
var uR = m.MultiplyPoint(new Vector3(camera.pixelRect.xMax, camera.pixelRect.yMax));

var rect = new Rect(uL.x, uL.y, Math.Abs(uR.x - uL.x), Math.Abs(bL.y - uL.y));


However, this does not take into account the orthographic size (zoom).

Multiplying the cameraToWorldMatrix with the camera's projectionMatrix property does not give me the correct results either.

Is there a sensible way that this can be solved?

        // Calculate orthographic camera bounds