One thousand grams is equal to one kilogram. The prefix "kilo" means 1,000. One kilogram is also about the same as 2 pounds, 3 ounces.
The unit "gram" is the base unit used to measure weight or mass in the metric system. The mass of one cubic centimeter of water at 4 degrees Fahrenheit is about the same as one gram. A paper clip's mass is about 1 gram.
Other metric units of mass include the metric ton, which is the same as 1,000 kilograms or 1 million grams. A centigram equals 100 grams, while a milligram is one-thousandth of a gram.