How to get distance from bottom of screen to a particular widget in flutter web?

Question

I need to calculate the distance from the bottom of a screen to a container.Is it possible to calculate distance from bottom of a screen to Container and distance from top of a screen to container in separately?

I got the distance from top like this,

 RenderBox box = keyGlobal.currentContext!.findRenderObject() as RenderBox;
              Offset position = box.localToGlobal(Offset.zero); //this is global position
              double y = position.dy;

Is it possible to get distance from bottom?