Get the viewport size of an orthographic camera in unity

BoundryFinder.cs

public class BoundryFinder : MonoBehaviour
{
  
	public float xMin, xMax, zMin, zMax;

	void Start()
	{
		GameObject sceneCamObj = GameObject.Find( "Main Camera" );
		Camera mainCam = sceneCamObj.GetComponent<Camera> ();
		Transform camPos = mainCam.transform;

		float vertExtent = mainCam.orthographicSize;
		float horzExtent = vertExtent * Screen.width / Screen.height;

		zMin = -vertExtent + camPos.position.z + 0.5f;
		zMax = vertExtent + camPos.position.z - 0.5f;
		xMin = -horzExtent + 0.5f;
		xMax = horzExtent - 0.5f;
	}
}