So in the year or so I've been brewing, I've just used Palmer's nomograph in the back of brewing classic styles to determine how much sugar to use when batch priming. I forget the exact wording off the top of my head, but it implies it is for a 5gal batch.
It occurred to me today that this might not be quite right. When I bottle, I'm not bottling exactly 5 gallons. I start w/ 5gal in the fermenter, but I lose some when transferring to the bottling bucket due to trub and I usually leave some beer at the bottom in an attempt to minimize sediment getting sucked up. I'd say that I probably end up with about 4.3 - 4.6 gallons in the bottling bucket.
Should I be accounting for this? It doesn't seem like a huge difference, and I've certainly never felt that my beers were consistently overcarbed (here and there, but it'd have to be a real trend if this were to be an issue) but at the same time if I end up with closer to 4 gallons of beer and am carbing for 5 gallons, that's nearly a 25% difference in volume of liquid.
Or perhaps calculators like Palmers take this into account - they're designed for a "5 gallon batch" with the understanding that not exactly 5 gallons will be going into bottles?