Convert from gallon [UK] to ounce [US, liquid]

Unit Definition (gallon [UK])
Currently the British use a larger gallon than either of the American gallons. The Imperial Weights and Measures Act of 1824 established a new unit for all volumes, liquid or dry, replacing all the other gallons in previous use in Britain. The imperial gallon, designed to contain exactly 10 pounds of distilled water under precisely defined conditions, holds exactly 4.546 09 liters or approximately 277.4194 cubic inches. The imperial gallon equals 1.20095 U.S. liquid gallons (British wine gallons) or 1.03206 U.S. dry gallons (British corn gallons).

Unit Definition (ounce [US, liquid])
The ounce [US, liquid] is a traditional unit of liquid volume, also called the fluid ounce to avoid confusion with the weight ounce. In the U. S. customary system there are 16 fluid ounces in a pint, so each fluid ounce represents 1.804 687 cubic inches or 29.573 531 milliliters. A U.S. fluid ounce of water weighs just a bit more than one ounce avoirdupois.