Are you are not taking a sleeping bag? Toiletries? Spares? Tools? Camera? Computer? Phone? Chargers? Batteries? If so I think you may have a problem with your scales.
My 'base weight' by that definition is 22kg, although that's assuming only 2 litres of water.
I don't take a camera, although in future I might take a little shock-proof Lumix. I've enough expensive hobbies without adding photography to the list. The only electronics I take are my Kindle and my iPhone, together with the Solarmonkey charger (400g). I also use a head torch, for which I carry two spare AAA batteries. I don't use a bike torch anymore, the head torch is enough.
That weight does include all of my toiletries - camping towel, baby wipes, toilet paper, talcum powder, roll-on deodorant, Pawpaw ointment and Sea to Summit multi-purpose wash, which I have found to be fine for shampoo, soap and clothes. I use the olive oil from my food bag as moisturiser, although I am usually wearing lots of greasy sunscreen anyway.
I take a relatively minimal toolkit (Leatherman pliers, chain breaker, spare links, allen keys, mini screwdriver, Torx key, tubes and patches etc). I don't take spare brake pads, tyres or a chain whip and casette removal tool, since my emergency spoke repair is a Fibrespoke. I also carry actual spokes (since DB spokes are surprisingly hard to find at most bike shops here) on my frame, but would need shop tools to install them. If I were going somewhere remote, I'd certainly take more tools.
I didn't include cycling clothing, since I wear most of it, but it would probably add to another kg or so.
I take a winter-weight fleece (600g) and a number of base layers, as well as a woollen beanie and gloves, for camp. I wear these under the cycling shells when it's very cold. I'd prefer a down jacket for camp in the winter, but they're expensive and what I have works fine. I've never camped anywhere really cold though, but this is about the same amount of clothing that I wear in German winters, so it should be ok.
By far the heaviest part of my kit is the camping stuff. Just removing the bag, tent, mat, ground sheet, pillow and stove would save me 5.3kg. Still, it doesn't make sense to me to lighten up on my camping gear much, since having a very warm sleeping bag (now the WM Apache), a four-season tent and a super-warm sleeping pad means that I need to carry less "just in case" cold weather gear. I could save about 1.5kg by purchasing a separate one-man tent, but I like having a huge tent.
Plus, the same $500 would buy me a gym membership for a year, which seems a more efficient way of carrying less weight...