DailyCalorieIntake-switch

using System;

class DailyCalorieIntake
{
    static void Main()
    {
        double weightInPounds = double.Parse(Console.ReadLine());
        double heightInInches = double.Parse(Console.ReadLine());
        double age = double.Parse(Console.ReadLine());
        char gender = char.Parse(Console.ReadLine());
        double workoutsPerWeek = double.Parse(Console.ReadLine());
        double weightInKg = weightInPounds / 2.2;
        double heightInSm = heightInInches * 2.54;
        double menBMR = 66.5 + (13.75 * weightInKg) + (5.003 * heightInSm) - (6.755 * age);
        double womenBMR = 655 + (9.563 * weightInKg) + (1.850 * heightInSm) - (4.676 * age);
        double? dci;

        if (workoutsPerWeek < 0)
        {
            workoutsPerWeek = 0;
        }

        switch ((int)workoutsPerWeek)
        {
            case 0:
                if (gender == 'm')
                {
                    dci = Math.Floor(menBMR * 1.2);
                }
                else
                {
                    dci = Math.Floor(womenBMR * 1.2);

                }
                break;
            case 1:
            case 2:
            case 3:
                if (gender == 'm')
                {
                    dci = Math.Floor(menBMR * 1.375);
                }
                else
                {
                    dci = Math.Floor(womenBMR * 1.375);
                }
                break;
            case 4:
            case 5:
            case 6:
                if (gender == 'm')
                {
                    dci = Math.Floor(menBMR * 1.55);
                }
                else
                {
                    dci = Math.Floor(womenBMR * 1.55);
                }
                break;
            case 7:
            case 8:
            case 9:
                if (gender == 'm')
                {
                    dci = Math.Floor(menBMR * 1.725);
                }
                else
                {
                    dci = Math.Floor(womenBMR * 1.725);
                }
                break;
            default:
                if (gender == 'm')
                {
                    dci = Math.Floor(menBMR * 1.9);
                }
                else
                {
                    dci = Math.Floor(womenBMR * 1.9);
                }

                break;
        }
        Console.WriteLine(dci);
    }
}