A gram is a small unit of measurement for weight in the metric system. One gram weighs about the same as a standard paper clip. To get a sense of how light that is, imagine that 28 grams equals about one ounce.

Scientists, cooks, and many people around the world use grams to measure precise amounts. A recipe might call for 250 grams of flour. A scientist might measure 5 grams of a chemical for an experiment. Doctors measure medicine doses in milligrams (thousandths of a gram) because accuracy matters so much.

The metric system, which includes grams, meters, and liters, makes calculations easier because everything works in multiples of ten. One thousand grams equals a kilogram, just like one thousand meters equals a kilometer. Most countries use the metric system as their standard, though the United States still primarily uses ounces and pounds for everyday measurements.

The word comes from the Greek gramma, meaning “small weight.”