DART

flutter get device width

double width = MediaQuery.of(context).size.width;

flutter: get height of Screen device

// All height of screen
double screenHeight = MediaQuery.of(context).size.height

// height of screen only
double screenHeight = MediaQuery.of(context).size.height -
    MediaQuery.of(context).padding.top -
    kToolbarHeight -
    kBottomNavigationBarHeight;