← Back to articles · Hobby & visiting shops ·
What a troy ounce is (the unit gold and silver actually use)
A troy ounce is 31.1035 grams. It is the unit for gold, silver, and platinum. It is heavier than a grocery-store ounce.
A troy ounce is the unit of weight for precious metal.
It equals 31.1035 grams. There are twelve troy ounces in a troy pound. Coin shops almost never say “troy pound.” They say ounces and grams.
It is not the kitchen ounce
The everyday US ounce is 28.35 grams. If you weigh a one-ounce gold coin on a food scale, the number will look wrong. The unit is wrong, not the coin.
The shop-floor version of this fight is here: troy vs regular ounce. This page is the definition.
Where you will see it
Spot prices are dollars per troy ounce. Bar stamps say 1 oz, 10 oz, or 1 kilo. Eagle, Maple, Krugerrand, and Libertad specifications are in troy ounces. Jewelry tickets often start in grams or pennyweight and get converted.
COMEX and LBMA. Karat math. What a kilo bar is.
More on the coin and money library.