Due to metrication, the United Kingdom (UK) no longer officially uses the ounce. By multiplying a given mass by the molar mass, the amount of moles of the substance can be calculated. The molar mass constant can be used to convert mass to moles. The ounce is still used in some other countries around the world that have roots in British history and culture. A substance’s molar mass is calculated by multiplying its relative atomic mass by the molar mass constant (1 g/mol). It is mostly used in the United States for measuring packaged food products, food portions, and postal items, among other things. The current definition of the ounce, the international avoirdupois ounce was adopted in 1959.Ĭurrent use: The ounce is still a standard unit of mass in the US customary system of measurement. Examples include the Dutch metric ounce (100g), French ounce (30.59g), and the Spanish ounce (28.75g), among others. The ounce has been used as a standard of mass throughout history for different applications and with different definitions. Then multiply the amount of Ounce you want to convert to Gram, use the chart below to guide you. This relationship between the Roman pound and foot eventually contributed to the uncia being the basis of the modern inch as well as the common ounce. To convert between Ounce and Gram you have to do the following: First divide 0.45359237/16 / 0.001 28.34952313. The copper bar was divided into twelve equal parts, called unciae. History/origin: The origin of the term ounce stems from the Roman uncia, which means a "twelfth part," and the use of a standardized copper bar which defined both the Roman pound and foot. The avoirdupois ounce (the common ounce) is defined as exactly 28.349523125 grams and is equivalent to one sixteenth of an avoirdupois pound. Ounceĭefinition: An ounce (symbol: oz) is a unit of mass in the imperial and US customary systems of measurement. Standards on the nutrition labels of food products often require the relative contents to be stated per 100 grams of the product. For example, the gram is typically used to measure non-liquid ingredients used for cooking or groceries. The gram was later redefined as one thousandth of a kilogram, the SI (meter-kilogram-second system of units) base unit of mass.Ĭurrent use: The gram is widely used in every life as well as scientific contexts. The gram used to be a fundamental unit of mass as part of centimeter-gram-second systems of units up until the widespread adoption of SI, which uses kilograms as the base unit of mass.
History/origin: Originally, a gram was defined as the absolute weight of pure water in a cubic centimeter at the temperature of melting ice (later 4 ☌). Since 2019, the definition of the kilogram is no longer based on the international prototype, and rather is based on Planck's constant, h, along with the new definitions of the second and the meter. The definition of the gram is based on the kilogram, where a gram is one thousandth of a kilogram, the SI base unit of mass. Definition: A gram (symbol: g) is a unit of mass in the International System of Units (SI).