Troy Ounces to Grams Converter

One troy ounce equals exactly 31.1034768 grams by international agreement. To convert troy ounces to grams, multiply the troy-ounce figure by 31.1034768. To go the other way, divide grams by 31.1034768. This is the unit used to quote and weigh gold, silver, platinum, and palladium.

A troy ounce (31.1035 g) is heavier than the standard avoirdupois ounce (28.349523125 g) found on food labels. A troy ounce is about 9.7% heavier, because 31.1034768 divided by 28.349523125 is roughly 1.0971. That is why a 1 oz gold coin weighs about 31.10 g, not 28.35 g, even though both are called an ounce.

Divide the weight in grams by 31.1034768. For example, a 100 g gold bar is 100 / 31.1034768, or about 3.2151 troy ounces. A 1 kilogram bar (1000 g) is about 32.1507 troy ounces, which is why kilo bars are sometimes quoted that way.

A troy pound is 12 troy ounces, not 16 like the avoirdupois pound. That works out to 12 times 31.1034768, or 373.2417216 grams. This calculator shows the troy-pound equivalent alongside grams, kilograms, and grains, so you can cross-check precious-metal weights.

The grain is the smallest unit in the troy system, with one troy ounce equal to exactly 480 grains. The grain (64.79891 mg) is still used for things like bullet weights and pharmacy measures, so the converter reports it so you can move between troy ounces, grams, and grains in one step.

Yes for the weight conversion itself, which is exact. Metal prices, however, change constantly and depend on purity (karat or fineness), premiums, and your dealer, so this tool gives you only the gram and troy-ounce weight, not a dollar value. Always confirm whether a price quote uses troy or avoirdupois ounces before you buy or sell.