I've been speaking to lots of Apiaries over the last few weeks trying to track down exactly which honey I want to buy, and the general rule of thumb that I've found useful is that 15 pounds is about 5 quarts, and hence 3 pounds = 1 quart (all very approximate). For those in Europe, a quart is a slightly undersized litre.
There are 16 ounces in a Pound (US or Imperial).
However if you use quarts and gallons it can get tricky depending on where you live, because a US Gallon is considerably smaller than an Imperial Gallon (that's why the cars in the UK get such great gas mileage compared to their colonial cousins)
1 Gallon [UK] = 160 Ounces [UK]
1 Gallon [Fluid, US] = 128 Ounces [Fluid, US]
Honey seems to be measured mostly in pounds, which is safe where ever you are, since a pound is a pound, the actual liquid volume that calculates to exactly will depend on the density of the honey, etc. and will become less accurate the greater the quantity being discussed.
Sorry for mini-essay, but I like to be clear.
Hope this helps a little?
Tony.