gram

The gram is a unit of mass in the metric system, symbol g. It is defined as one thousandth of a kilogram, so 1 g equals 0.001 kg and 1 kg equals 1000 g. The gram is a derived unit widely used in everyday measurements and is common in science, medicine, cooking, and industry. In practice, masses are often expressed in grams or in related units such as milligrams (mg) and kilograms (kg).

Historically, the gram was introduced with the metric system in the late 18th century. It was originally defined as the mass of one cubic centimeter of water at its maximum density (around 4°C). The kilogram, the base unit of mass in the International System of Units (SI), was defined as the mass of a prototype artifact kept at the International Bureau of Weights and Measures. In 2019, the SI redefinition established the kilogram in terms of fundamental constants, but the gram remained the simple 1/1000 of a kilogram.

The gram is widely used alongside other mass units. In science, it is common for small quantities, while larger masses are expressed in kilograms. Nutritional labels, pharmaceutical preparations, and laboratory measurements frequently report masses in grams. The unit is accepted for use with the SI and is universally understood in most countries, reinforcing the gram’s role as a practical standard for everyday measurement.