flutter_size 0.0.3

You can add and get custom size,orientation of any type of widgets. In size, you can add and get width,height of the device and widgets and You also get the full height and width of particular devices [...]

example/example.dart

import 'package:flutter/material.dart';
import 'package:flutter_size/flutter_size.dart';

class ExampleScreen extends StatefulWidget {
  const ExampleScreen({Key? key}) : super(key: key);

  @override
  State<ExampleScreen> createState() => _ExampleScreenState();
}

class _ExampleScreenState extends State<ExampleScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: SizedBox(
          width: context.width(0.4),
          height: context.height(0.3),
          child: const Text("Example"),
        ),
      ),
    );
  }
}