Ounce (oz) - Unit Information & Conversion
What is a Ounce?
Definition
The ounce (oz) is a unit of mass used in the British imperial and United States customary systems of measurement. The most common type today is the international avoirdupois ounce, defined as exactly 1/16 of an avoirdupois pound, or approximately 28.35 grams.
History
The term "ounce" derives from the Roman "uncia", which was one-twelfth of the Roman pound. Its value varied throughout history and regions. The avoirdupois ounce became standardized in the English-speaking world for general trade.
Common Uses
- Cooking & Recipes: Standard unit in the US for measuring food ingredients like flour, sugar, spices, and non-liquid items in recipes.
- Packaged Foods: Used for labeling the net weight of many packaged food products (e.g., cereal boxes, canned goods, snacks).
- Postal Services: Used for determining the weight and cost of letters and small parcels, especially in the US.
- Deli & Groceries: Common unit for measuring small portions of items like cheese, deli meats, and specialty foods.
- Precious Metals: Often used to measure the weight of gold, silver, and other precious metals in jewelry and bullion.
Unit FAQs
How many ounces are in a pound?
There are 16 avoirdupois ounces (oz) in 1 pound (lb).
Is an ounce the same as a fluid ounce?
No. The ounce (oz) measures mass/weight, while the fluid ounce (fl oz) measures volume.
Where is the ounce commonly used?
It is primarily used in the United States for everyday measurements, and to some extent in the UK and Canada, though metric units are more prevalent globally.
Ounce Conversion Formulas
To Kilogram:
To Gram:
To Milligram:
To Pound:
To Stone:
To Ton (metric):
To Ton (US):
To Ton (UK):
To Microgram:
To Carat:
To Slug:
To Troy Ounce:
To Pennyweight:
To Grain:
To Dram:
To Quintal:
To Atomic Mass Unit:
To Pavan (India):
To Kati (India):
To Masha (India):
To Dina (India):
To Pras (India):
To Lota (India):
Convert Ounce
Need to convert Ounce to other weight units? Use our conversion tool.