Convert ounces to grams (2024)

Please provide values below to convert ounce [oz] to gram [g], or vice versa.

Ounce

Definition: An ounce (symbol: oz) is a unit of mass in the imperial and US customary systems of measurement. The avoirdupois ounce (the common ounce) is defined as exactly 28.349523125 grams and is equivalent to one sixteenth of an avoirdupois pound.

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 copper bar was divided into twelve equal parts, called unciae. 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. The ounce has been used as a standard of mass throughout history for different applications and with different definitions. Examples include the Dutch metric ounce (100g), French ounce (30.59g), and the Spanish ounce (28.75g), among others. The current definition of the ounce, the international avoirdupois ounce was adopted in 1959.

Current use: The ounce is still a standard unit of mass in the US customary system of measurement. It is mostly used in the United States for measuring packaged food products, food portions, and postal items, among other things. The ounce is still used in some other countries around the world that have roots in British history and culture. Due to metrication, the United Kingdom (UK) no longer officially uses the ounce. It is however, still used in some settings in the UK, such as restaurants.

Gram

Definition: A gram (symbol: g) is a unit of mass in the International System of Units (SI). 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. 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.

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 °C). 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. The gram was later redefined as one thousandth of a kilogram, the SI (meter-kilogram-second system of units) base unit of mass.

Current use: The gram is widely used in every life as well as scientific contexts. For example, the gram is typically used to measure non-liquid ingredients used for cooking or groceries. Standards on the nutrition labels of food products often require the relative contents to be stated per 100 grams of the product.

Ounce to Gram Conversion Table

How to Convert Ounce to Gram

1 oz = 28.349523125 g
1 g = 0.0352739619 oz

Example: convert 15 oz to g:
15 oz = 15 × 28.349523125 g = 425.242846875 g

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