Android: Floating Button Icon is not centred

I just set the app:fabCustomSize=”40dp” (needed size) and I set the height and width as wrap_content then issue solved

I have faced the same problem. the following solution have worked for me

app:fabCustomSize="40dp"

You should set fabCustomSize value like FAB exactly size:

<android.support.design.widget.FloatingActionButton
        android:layout_width="60dp"
        android:layout_height="60dp"
        app:fabCustomSize="60dp"
        android:src="@drawable/plus_icon"
        app:rippleColor="@color/colorPrimaryDark" />