Find folder size in asp.net

use these code

protected void Page_Load(object sender, EventArgs e)
{
    Response.Write(FindFolderSize(new DirectoryInfo(Server.MapPath("~")), UnitType.KB, 0).ToString() + " KB");
    Response.Write(FindFolderSize(new DirectoryInfo(Server.MapPath("~")), UnitType.MB, 2).ToString() + " MB");
    Response.Write(FindFolderSize(new DirectoryInfo(Server.MapPath("~")), UnitType.GB, 5).ToString() + " GB");
}

public enum UnitType { KB = 1, MB = 2, GB = 3 }
///
/// Find folder size
///
/// Target folder
/// Unit type [KB, MB, GB]
/// Number to digits to round up
///

public double FindFolderSize(DirectoryInfo d, UnitType u, int r)
{
    double divider = Math.Pow(1024, (int)u);
    double size = 0;
    foreach (FileInfo f in d.GetFiles())
        size += Convert.ToDouble(f.Length) / divider;
    foreach (DirectoryInfo c in d.GetDirectories())
        size += this.FindFolderSize(c, u, r);
    return Math.Round(size, r);
}