The unit of measurement for gold is troy ounces, not regular ounces, and one gram is equal to 0.03215 troy ounces. Dividing both sides of this equation by 0.03215 finds that there are 31.1 grams in one troy ounce of gold.
It is possible to convert this result to regular, or avoir, ounces, although it is not usually necessary. One regular ounce equals 0.911458 troy ounces. Dividing both sides of this equation by 0.911458 finds that one troy ounce is equal to 1.097 regular ounces. Those who want to convert one regular ounce of gold to grams can use an online converter. One regular ounce of gold equals around 28.35 grams.