The equivalent of 250 milliliters is approximately 8.45 U.S. fluid ounces, or slightly more than 1 cup. The equivalent of 1 milliliter is about 0.03 U.S. fluid ounce. Milliliters and ounces are both units of volume but in different systems of measurement.
The milliliter, which is 0.001 liter, is a unit in the metric system. This system is used throughout most of the industrialized world. The United States, however, uses U.S. customary units derived from the imperial system of measurement. Ounces and pounds are units in this system. These units, along with such others as cups and pints, are used in recipes in the United States.