Everyday things, although we seldom say so, are measured in Avoirdupois units. There are 16 ounces in an Avoirdupois pound, while there are only twelve ounces in a Troy pount.
Troy ounces to the Avoirdupois ounce.
If it helps, a Troy ounce weighs 31.1033 grams, while an Avoirdupois ounce weighs 28.3495 grams. A Troy pound weighs 373.2396 grams, and an Avoirdupois pound weighs 453.592 grams. Finally, precious metals are also measured by the pennyweight, which is abbreviated as dwt, and by grains. There are 20 pennyweights or 480 grains in a Troy ounce. Gold comes in several forms in jewelry.