What is oz?

An ounce (abbreviated as "oz") is a unit of measurement that comes in two forms:

  • Fluid ounces (fl oz): Used for measuring liquids
  • Weight/mass ounces: Used for measuring dry ingredients

Fluid Ounces

  • 1 fluid ounce = approximately 29.57 milliliters
  • 8 fluid ounces = 1 cup
  • 16 fluid ounces = 1 pint
  • 32 fluid ounces = 1 quart
  • 128 fluid ounces = 1 gallon

Common examples in cooking:

  • A typical can of soup contains about 10-12 fl oz
  • A standard soda can holds 12 fl oz
  • Most recipes calling for milk or water use fluid ounces

Weight Ounces

  • 1 weight ounce = approximately 28.35 grams
  • 16 weight ounces = 1 pound

Common examples in cooking:

  • A stick of butter is 4 oz
  • Pasta serving sizes are often listed as 2 oz
  • Meat portions are commonly measured in ounces (e.g., an 8 oz steak)

Historical Background

The word "ounce" comes from the Latin "uncia," meaning "a twelfth part" (originally referring to 1/12 of a Roman pound). The abbreviation "oz" comes from the old Italian word "onza."

Tips for Beginners

  1. Always check if a recipe means fluid or weight ounces
  2. Use proper measuring tools:
    • Liquid measuring cups for fluid ounces
    • Kitchen scales for weight ounces
  3. Don't try to measure fluid ounces in a dry measuring cup
  4. Remember that fluid ounces and weight ounces are not interchangeable (except for water, where 1 fl oz = 1 oz by weight)

Digital Age Conversion

Most modern phones have built-in conversion tools, or you can use voice assistants to quickly convert between:

  • Ounces to grams
  • Ounces to milliliters
  • Ounces to cups
  • Ounces to pounds