just found this thread! Just like you I've been tracking my gear with Excel and find it frustrating having to enter each detail and trying to think of those details as well. The calculator is really well done (love the background too) and I'd say is a pretty useful "guesstimator" for what any given pack might weigh.

For those who are "Meh!" because it doesn't list the actual weight of your particular gear, then enter that gear with it's weight (that you've actually weighed). I like it and will use it from now on. The spreadsheet I have now will be strictly for archival/tracking purposes. When I load out for a trip, it'll be the online weight converter.