How to check the size of the folder inside a Amazon S3 bucket.

might got the answer with the help of frndz i think: (This might be the way to do that)

Public Shared Sub CheckUserFolderSize(ByVal s3Client As AmazonS3, ByVal bucketName As String, ByVal folderName As String)

Try
Using (s3Client)

Dim totalFileSize As Long
Dim maxSize As Long = 1.0
'assuming your delimiter is a /
Dim Lor As New ListObjectsRequest() With { _
.BucketName = bucketName, _
.Prefix = folderName, _
.Delimiter = "/" _
}

Dim response1 As ListObjectsResponse = s3Client.ListObjects(Lor)

For Each s3Object As S3Object In response1.S3Objects
totalFileSize += s3Object.Size()
Next

If totalFileSize > maxSize Then

End If
End Using
Catch ex As Exception

End Try

End Sub

here Folder name is the prefix, as we don't have the directory structure in the Amazon S3.
Thanks and Regards.