A gallon is the primary unit of liquid measure in the US, holding 128 fluid ounces (fl oz). An ounce (fl oz) is the smaller unit, equivalent to 2 tablespoons or 1/8 cup. Commonly used liquid measurement units include half gallons (64 fl oz), quarts (32 fl oz), pints (16 fl oz), and cups (8 fl oz). Milk jugs typically hold half gallons. Measuring cups and spoons come in various sizes to accommodate different liquid volumes. Accurate liquid measurement is essential in cooking and baking. Conversion charts provide quick references for converting between different liquid units.