From http://www.w3schools.com (Copyright Refsnes Data)

ADO Size Property

Stream Object Reference Complete Stream Object Reference

The Size property returns a long value that indicates the size (in bytes) of a Stream object.

Note: This property can only be used on an open Stream object.

Note: This property returns -1 if the size of the stream is unknown.

Syntax

objStream.Size

Stream Object Reference Complete Stream Object Reference

From http://www.w3schools.com (Copyright Refsnes Data)