What is difference between a troy ounce and a regular ounce?
The ounce (abbreviated: oz, the old Italian word onza, now spelled oncia) is a unit of mass in a number of different systems, including various systems of mass that form part of the imperial and United States customary systems. Its size can vary from system to system. The most commonly used ounces today are the international avoirdupois ounce and the international troy ounce. The avoirdupois ounce is the most commonly used ounce today. It is defined to be one sixteenth of an avoirdupois pound. It is therefore equal to 437.5 grains. In 1958 the United States and countries of the Commonwealth of Nations agreed to define the international avoirdupois pound to be exactly 0.45359237 kilograms. Consequently, since 1958, the international avoirdupois ounce is exactly 28.349523125 grams by definition. The ounce is commonly used as a unit of mass in the United States. While imperial units have been officially abolished in the United Kingdom, the ounce remains a familiar unit, especially amongst
