How Do You Convert Troy Ounces to Grams?
Multiply troy ounces by 31.1035 to get grams. The formula is: Grams = Troy Ounces x 31.1035. The troy ounce is defined as exactly 31.1034768 grams, commonly rounded to 31.1035.
Tom Brewer evaluates gold coins for his investment portfolio. A 1-ounce American Gold Eagle contains exactly 1 troy ounce of pure gold = 31.1035 grams. The coin actually weighs 33.93 grams total because it also contains copper and silver for durability. He calculates the gold value at $2,100/ozt: the gold content alone is worth $2,100.
Precious Metal Weight Reference
| Troy Ounces | Grams | Common Form |
|---|---|---|
| 1/10 ozt | 3.11 g | Small gold coin |
| 1/4 ozt | 7.78 g | Quarter eagle coin |
| 1/2 ozt | 15.55 g | Half-ounce bar |
| 1 ozt | 31.10 g | Standard bullion coin |
| 5 ozt | 155.52 g | 5-ounce bar |
| 10 ozt | 311.03 g | 10-ounce bar |
| 100 ozt | 3,110.35 g | 100-ounce silver bar |
| 400 ozt | 12,441.40 g | London Good Delivery bar |
Practical Applications
Gold Investment
Sam Okafor helps a client diversify into physical gold. They purchase 25 troy ounces in 1-ounce coins = 25 x 31.1035 = 777.6 grams of gold. At $2,100 per troy ounce, the investment totals $52,500 for 777.6 grams. He explains that gold density (19.3 g/cm3) means this amount is surprisingly compact: only about 40 cubic centimeters, roughly the size of a golf ball.
Jewelry Manufacturing
Leah Novak sources gold for custom jewelry. She buys 3 troy ounces of 18K gold wire = 93.3 grams. Since 18K gold is 75% pure, the actual gold content is 69.98 grams = 2.25 troy ounces. She makes 15 pendants using about 6.2 grams each. Material cost per pendant at $2,100/ozt: 6.2 g / 31.1 g/ozt x $2,100 = $418.65 in gold alone.
Coin Collecting
Marco Ferreira starts a silver coin collection. A 1-ounce Silver Eagle weighs 31.1 grams of pure silver in a 31.1-gram coin (unlike gold coins, silver coins contain no base metal). He buys a roll of 20 coins = 20 ozt = 622.1 grams. At $28 per troy ounce, the silver value is $560. The coins trade at $32 each ($640 total) due to numismatic premium.