Example showing dynamic height of rounded bottomSheet,This sheet gets scrollable when it exceeds the Max available height originally posted: https://stackoverflow.com/a/64504274/8253662

dynamic_bottomSheet_height.dart

// Copyright (c) 2019, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      debugShowCheckedModeBanner: false,
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {

  Widget _item(int index) {
    return SwitchListTile(
        title: Text('Item $index'), value: false, onChanged: (x) {});
  }

  Future<void> _showBottomSheet() async {
    return showModalBottomSheet(
      isScrollControlled: true,
      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(13)),
      backgroundColor: Colors.white,
      context: context,
      builder: (context) => Padding(
          padding: EdgeInsets.only(top: MediaQuery.of(context).padding.top),
          child: SingleChildScrollView(
              child: Column(
                  crossAxisAlignment: CrossAxisAlignment.center,
//               mainAxisSize: MainAxisSize.min,
                  children: List.generate(kItems, (index) => _item(index))))),
    );
  }

  int kItems = 6;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
           Text(
              'Example showing dynamic height of Rounded bottom Sheet \n\n modify kItems to see the dynamic height of the bottom sheet',
              textAlign: TextAlign.center,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () => _showBottomSheet(),
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}