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Dunn To PerfectionFoundation

Gold Foundations · Module 1: What Is Gold? · Lesson 4

What Is a Troy Ounce?

Beginner 4 minLesson 4 of 29

Learning objectives

  • Explain the difference between a troy ounce and a regular ounce

Two different ounces

The everyday (avoirdupois) ounce is about 28.35 g. The is about 31.10 g — roughly 10% heavier. Precious metals are always quoted in troy ounces.

The name traces back to Troyes, a French market town where the unit was standardised in medieval trade fairs.

Gold weights at a glance

1 troy oz

31.10 g

1 regular oz

28.35 g

1 kilogram

32.15 troy oz

Good Delivery bar

≈400 troy oz

Key takeaways

  • Troy ounce ≈ 31.10 g; regular ounce ≈ 28.35 g.
  • All gold prices are per troy ounce.

Knowledge check

A troy ounce compared with a regular ounce is…

Key terms · hover or tap for a definition

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