Hey, look, I made it.
I'm on track (more or less) to walk 2100 miles by the end of the year. I only need 2000; that is my story and I'm sticking to it. Being ahead is good, of course, because it gives me a nice amount of wiggle room; at some point I'm probably going to get sick, or stub my toe, or have a really low-mileage week for other reasons (Comic-Con's going to be a disaster in that department, I'm sure).
I'm never quite sure how to measure what I'm on track for. It'll be interesting to see to how many extra miles I have in by July 2nd, the midpoint of the year. I've been using average miles per day to estimate a total for the year, but averaging out six months of data isn't really that useful.
This whole thing is composed of estimates, guesses and approximations, of course. The fitbit is a reasonably accurate pedometer, but it's not perfect, and under some circumstances it over-counts steps. (I compensate for this somewhat by taking it off when I get home from work. And because I am not wearing a bra all damn night. My dedication does not go that far.) I never calibrated it for my stride, though I'm fairly sure it's accurate-to-slightly-undercounting mileage. That also helps balance out any over-counted steps, and in any case, I wouldn't want to switch calibration partway through the year. If there's an adjustment to be made (ie, if calibration indicates it was over-counting miles after all), I'll make it at the end of the year.
The details are not, ultimately, that important, but all this stuff makes me feel like I'm getting credit for the walking I do, which in turn makes me feel motivated to keep doing it (though it's such an ingrained habit now that I doubt I could stop).
So. I did that. Now I just have to do it again.