Gold Weight: Troy Ounces Explained

When gold is priced at "$2,000 per ounce," it is not the same ounce you use in cooking. Gold, silver, and other precious metals use the troy ounce — a heavier, older unit. Here is why, and how to convert.

Troy Ounce vs Regular Ounce

Why Use a Different System?

The troy system dates back to medieval Troyes, France — a major trading hub. It persists because:

• ▶ The precious metals market is global and centuries old
• ▶ Changing units would cause chaos in contracts and pricing
• ▶ All international gold trading uses troy ounces by convention
• ▶ It provides a standardised measure everyone in the industry understands

Key Conversions

• ▶ 1 troy ounce = 31.1035 grams
• ▶ 1 troy ounce = 1.097 regular ounces
• ▶ 1 troy pound = 12 troy ounces (not 16 like regular pounds)
• ▶ 1 kilogram = 32.15 troy ounces
• ▶ 1 gold bar (standard) = 400 troy ounces ≈ 12.4 kg

Putting It in Context

• ▶ Gold coin (1 oz): 31.1g — about the weight of 6 UK pound coins
• ▶ Gold bar (1 kg): 32.15 troy oz — fits in your palm but weighs as much as a bag of sugar
• ▶ Olympic gold medal: Only ~6g of actual gold (the rest is silver)