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
- Always check if a recipe means fluid or weight ounces
- Use proper measuring tools:
- Liquid measuring cups for fluid ounces
- Kitchen scales for weight ounces
- Don't try to measure fluid ounces in a dry measuring cup
- 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