**Conversion of ounces to liters depends on which unit of ounce is being referred to.** A half liter of liquid is equivalent to 17.5975 fluid ounces or 16.907 U.S. ounces.

One liter is equivalent to 35.195 fluid ounces or 33.814 U.S. customary fluid ounces. Ounce and liter are both units of measurement for volume, which refers to the quantity of space that a substance occupies. Liter is a volumetric unit of measurement in the metric system, while ounce is part of either the imperial system or the U.S. customary measurement system. Several references use the term ounce to refer to U.S. customary fluid ounces.

The imperial units system is a set of units governed by the British Weights and Measures Act of 1824. This superseded the earlier measurement system known as English units, which brought forth units such as foot, yard, acre, quart and gallon. Meanwhile, the U.S. customary units system consists of units that appear similar to the imperial system but with several differences. While the measurements for inch and foot are the same for both systems, many of the volumetric units differ in measurement. Aside from the difference in ounces, 1 gallon in the imperial system is equivalent to 4.546 liters, while 1 U.S. gallon is equal to 3.785 liters.