A 2-liter bottle holds 67.6 fluid ounces of liquid, as there are 33.8 fluid ounces per liter. Liter bottles are often used to hold liquids that are measured by size rather than weight, such as soda and beer.
The liter was first used as a measurement by the French metric system, where it was a base unit with a capacity of 0.831 modern liters. Today, the International Bureau of Weights and Measures defines a liter as the equivalent volume of a cubic decimeter or 1000 cubic centimeters. A liter of water or another equivalent liquid has a mass of approximately 1 kilogram.