U.S. citizens use the standard measurement system, otherwise known as English units or U.S. customary units, to measure liquids and masses. Converting between one measurement of a liquid, such as a gallon, to another, such as a quart, requires some rote memorization.

Converting Units

To calculate uncommon conversions, such as from a half gallon to other fluid units of measure, you must know or look up units in the standard measure system. Fortunately, there aren't that many to memorize. One gallon is equivalent to any of the following -- 4 quarts, 8 pints, 16 cups or 128 fluid ounces.

Divide by Two

If you want to know how much of each fluid measure a half gallon contains, simply divide the standard measurements by two. One half gallon, therefore, is equivalent to any of the following -- 2 quarts, 4 pints, 8 cups or 64 fluid ounces.