How many grams is one ounce of gold?

Most people associate the ounce with the Imperial or U.S. customary unit of weight equal to about 28.3 grams and abbreviated to “oz”, also known as the avordupois ounce.

This unit is used for weighing groceries in the USA and, less frequently, in UK.

However, another ounce, so called troy ounce, is used for indicating the weight of precious metals, including gold, silver, etc. It is equal to ca. 31.3 grams.

Below you will find a comparison of the two units described above and their exact weight conversion to grams:

	Weight [g]	Use
1 avoirdupois ounce	28.349523125	For weighing groceries
1 troy ounce	31.1034768	For weighing gold

Did you know?

1. The troy ounce as well as the avoirdupois ounce can be further broken down into grains. The troy ounce weighs 480 grains and the avoirdupois ounce: 437.5 grains. The grain is also a unit used in archery for weighing arrows.
2. The name “troy ounce” is allegedly related to Troyes, a city in France.
3. The avoirdupois system was developed for the purposes of wool trade in the Middle Ages.
4. There have been many different units known as ounce throughout history. One of such obsolete units was the apothecaries’ ounce.

Have you heard of any other ounces?