>> Oh, sure, a hogshead is 63 gallons, but that's clearly just an off-by-one >> error. > > That's almost 1/16 of a kilogallon (and by kilogallon, I mean 1,024 > gallons, not 1,000 gallons). So you mean a kibigallon not a kilogallon: http://en.wikipedia.org/wiki/Binary_prefix#IEC_standard_prefixes