I don't measure it exactly, but I think it's close for me. I usually have a bottle of plain seltzer water (no sodium, calories, sugar, plain carbonated) open that I drink from throughout the day. My husband also always has a 2 liter bottle of seltzer at hand. We switch between that and Perrier mineral water, easy way to get your daily intake. In fact I'm drinking some cold Perrier right now.
Back when I was still working I had a bout of self-diagnosed dehydration. For a day or two I was seeing little floaters to the side of my head in my peripheral vision, and I was getting dizzy spells. That's when I got serious about drinking more water, and was bringing a small bottle of filtered tap water with me to work everyday, sometimes I'd add a dash of natural lemon juice to it for flavor. The lemon I had heard was also good for the body's alkalinity, and that's a good thing. Drinking coffee in the morning and on my first break without adding some water is what I think caused the problem.
Lon, what lab test did he do to show dehydration?