alt Hacker NewsI think being consistently inaccurate helps. If you always get the same thing at a certain restaurant, you can start by giving your best estimate of the calories in that meal. Then if your average weight doesn't move in the direction you want you can adjust your target calories to compensate.
That probably doesn't work either unless they work in an automated fashion. Did the chef put two or three dashes (official SI unit) of this or that on your meal? A a "dash" or "splash" or "spritz" of certain things can easily mean 100-200 kcal. And if you deal with things like meat, maybe the cut you get today is more or less lean than what you got last week.
I think tracking calories for a couple of weeks can be very enlightening for a lot of people, granted you don't have a personality type where this can get you into trouble. But for the long haul it's not really useful or even feasible, you're better off getting to know what sort of way of eating suits you best and how to correct if you're getting off course. Anyone can stick to a very strict regime for three months, but the trick is to stick to a proper diet you can enjoy for three decades and then three decades more.