What is the Difference Between Ounce and Troy Ounce?

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The main difference between an ounce and a troy ounce lies in their weight and the types of materials they are used to measure. Here are the key differences:

  1. Weight: A troy ounce is heavier than a regular ounce. One troy ounce is equal to 31.1 grams, while a regular ounce (also known as an avoirdupois ounce) is equal to 28.35 grams. This makes a troy ounce approximately 10% heavier than a regular ounce.
  2. Measurement Units: The troy ounce is used to measure precious metals and gems, such as gold and silver. In contrast, the regular ounce is used to measure other commodities, such as food and non-precious metals.
  3. Origin: The troy ounce system dates back to the 16th century French town of Troyes, which was an important trade center that standardized the troy ounce as 480 grains of barley. The avoirdupois ounce, or regular ounce, is a standard used in the US to measure foods and other items, with the exception of precious metals and gems.

It is essential to understand the difference between these two units of measurement, as they are not interchangeable and are used for different purposes. Knowing the weight of precious metals in troy ounces helps maintain purity standards and ensures a standardized unit of measurement for the international precious metals market.

Comparative Table: Ounce vs Troy Ounce

The main difference between an ounce and a troy ounce lies in their weight and the substances they are used to measure. Here is a table comparing the two units of measurement:

Troy Ounce (oz t) Ounce (oz)
31.1035 grams 28.3495 grams
Used for precious metals and gems Used for food and other items, except precious metals and gems
One troy pound equals 12 oz t One avoirdupois pound equals 16 oz
Troy ounces are heavier than avoirdupois ounces Avoirdupois ounces are lighter than troy ounces

A troy ounce is a unit of measurement primarily used for weighing precious metals like gold, silver, and platinum, and is heavier than a standard ounce (avoirdupois ounce). One troy ounce weighs 31.1035 grams, while a standard ounce weighs 28.3495 grams. Troy ounces are used in the precious metals industry worldwide to ensure consistency in purity and measurement. In comparison, standard ounces are used to measure common items like food and other substances.