(Android) Create bounding box with map markers and get width of it in Google Map V2

I'm using the following code to zoom and show all markers on a GoogleMap in Android. It works well:

LatLngBounds.Builder builder = new LatLngBounds.Builder();

//the include method will calculate the min and max bound.
builder.include(marker1.getPosition());
builder.include(marker2.getPosition());
builder.include(marker3.getPosition());
builder.include(marker4.getPosition());

LatLngBounds bounds = builder.build();

int width = getResources().getDisplayMetrics().widthPixels;
int height = getResources().getDisplayMetrics().heightPixels;
int padding = (int) (width * 0.10); // offset from edges of the map 10% of screen

CameraUpdate cu = CameraUpdateFactory.newLatLngBounds(bounds, width, height, padding);

mMap.animateCamera(cu);

But what I want to do is map all the markers in a bounding box and then get the width of that box. How can I do that?

from (Android) Create bounding box with map markers and get width of it in Google Map V2