Bullion basics
Troy ounces and bullion weights
Updated · General information, not financial advice
What is a troy ounce?
The troy ounce is the standard unit for weighing and pricing gold, silver, platinum and palladium. International spot prices are quoted per troy ounce, and “1 oz” on a bullion product means one troy ounce.
| Unit | Grams | Troy ounces |
|---|---|---|
| 1 troy ounce | 31.1035 g | 1 |
| 1 ordinary (avoirdupois) ounce | 28.3495 g | 0.9115 |
| 1 kilogram | 1,000 g | 32.1507 |
| 100 grams | 100 g | 3.2151 |
Common bullion sizes
Bullion is produced in both metric and troy-ounce sizes. Typical examples include:
- Gold bars: 1 g, 5 g, 10 g, 20 g, 1 oz, 50 g, 100 g, 10 oz and 1 kg.
- Gold coins: 1/10 oz, 1/4 oz, 1/2 oz and 1 oz.
- Silver: 1 oz coins and rounds, and bars of 10 oz, 1 kg and larger.
Because silver costs far less per ounce than gold, the same sum buys much more silver by weight. 1,000 troy ounces of silver weighs about 31 kg.
Gross weight and fine weight
Gross weight is the total weight of the item; fine weight is the weight of pure metal it contains. For 999.9 products the two are effectively the same; for alloyed coins such as 22 carat gold, the gross weight is higher. See bullion purity explained.
This guide is general information only and does not take into account your objectives, financial situation or needs. HLBullion does not provide financial, taxation or legal advice.