Understanding Gold Measurements

Learn about the different ways gold is measured, including weight and purity in karats.

What is an "oz" in Gold?

An "oz" in gold refers to a troy ounce, a unit of weight specifically used for measuring precious metals like gold, silver, and platinum. The troy ounce is different from the standard (avoirdupois) ounce used for other goods.

Key Details:

  • Weight:
    • 1 troy ounce = 31.1035 grams.
    • It is heavier than the standard ounce, which weighs 28.3495 grams.
  • Usage:
    • The troy ounce is the standard unit of measure in international markets for gold and other precious metals.
    • Gold prices are typically quoted per troy ounce.
  • Historical Context:
    • The troy ounce originated from the Troyes market in France during the Middle Ages and has been used in the bullion and precious metals markets for centuries.
  • Conversion to Grams and Other Units:
    • 1 kilogram (kg) = 32.1507 troy ounces.
    • For everyday use, gold can also be measured in grams, kilograms, or tolas (in South Asia).

Gold Purity Measurements (Karats)

Gold purity is commonly measured in karats (K). A karat is a unit that measures the purity of gold, with pure gold being 24 karats. The higher the karat number, the purer the gold.

Gold Purity Scale:

  • 24K: Pure gold (99.9% pure).
  • 22K: 91.67% pure gold (most common in jewelry).
  • 18K: 75% pure gold.
  • 14K: 58.33% pure gold.
  • 10K: 41.67% pure gold (minimum legal gold purity in the U.S.).