kilogram

American  

[kil-uh-gram] / ˈkɪl əˌgræm /

especially British, kilogramme

noun

• kilograms
  plural

1. a unit of mass equal to 1,000 grams: the basic unit of mass in the International System of Units (SI). Up until 2019 the kilogram was defined as equal to the mass of an international prototype, a platinum-iridium cylinder kept in Sèvres, France. The kilogram has since been redefined in terms of universal physical constants, including the speed of light and Planck's constant. kg

2. a unit of force and weight, equal to the force that produces an acceleration of 9.80665 meters per second per second when acting on a mass of one kilogram. kg

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kilogram British  

/ ˈkɪləʊˌɡræm /

noun

1. one thousand grams

2. the basic SI unit of mass, equal to the mass of the international prototype held by the Bureau International des Poids et Mesures. One kilogram is equivalent to 2.204 62 pounds

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kilogram Scientific  

/ kĭl′ə-grăm′ /

1. The basic unit of mass in the metric system, equal to 1,000 grams (2.2 pounds).

2. See Table at measurement

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kilogram Cultural  

1. A unit of mass in the metric system, equal to one thousand grams. The weight of a one-kilogram mass is slightly over two pounds.

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Other Word Forms

Noun Inflected Forms

• kilograms
  plural

Etymology

Origin of kilogram

From the French word kilogramme, dating back to 1790–1800. See kilo-, -gram ²

Explanation

A kilogram is a unit of measurement that's a bit more than two pounds. The liter bottle of soda in your refrigerator weighed about one kilogram when it was full. The United States is one of only three countries that has not adopted the metric system as its official system of measurement. In the United States, then, the pound is the basic unit used to measure mass, while most countries use the kilogram. So your bulldog weighs in at 100 pounds at your home in Florida but 45.36 kilograms when you move to Ireland. Originally, a kilogram was defined as the mass of a liter of water.

Example Sentences

See Examples For:

kilogram kilograms

"You would need the best part of a kilogram of raw chicken a day to get the amount of creatine you need," says Close.

From BBC ● Aug. 20, 2026

Larger rockets like SpaceX’s Falcon Heavy, which can put almost 64 metric tons into low-Earth-orbit, can keep the cost per kilogram of cargo at about $1,500.

From The Wall Street Journal ● Jun. 5, 2026

Of the 100 homes sampled, 17 had lead levels above 80 milligrams per kilogram, California’s benchmark for residential properties.

From Los Angeles Times ● May 21, 2026

SpaceX’s workhorse launch vehicle can carry 22,500 kg to orbit at $3,289 a kilogram.

From MarketWatch ● May 21, 2026

Even botulism, the deadliest toxin ever known, needed at least 1 nanogram per kilogram to kill a human.

From "The Last Cuentista" by Donna Barba Higuera

Native -- a trendy bar in Singapore that made this year's Asia's 50 Best Bars list -- imports around 900 kilograms of ice from Kuramoto each year.

From Barron's ● Sep. 6, 2026

But then there were proposals to increase capacity to make five million more kilograms of PCBs at their plant in Newport.

From BBC ● Aug. 10, 2026

The hapless sunfish can weigh up to 2,000 kilograms and is distinct for both its size and peculiar shape featuring a flattened body and fins.

From Barron's ● Jul. 23, 2026

By comparison, those receiving standard care lost only about two kilograms.

From Science Daily ● Jul. 8, 2026

Turns out, through a neat set of chemical reactions with the Martian atmosphere, for every kilogram of hydrogen you bring to Mars, you can make thirteen kilograms of fuel.

From "The Martian" by Andy Weir