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

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Etymology

Origin of kilogram

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

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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

"The price of a kilogram of meat ranges between 50,000 and 70,000 pounds. If you could previously afford to buy two kilograms of meat, today you will buy 125 grams."

From Barron's ● Nov. 5, 2026

SpaceX, he adds, has cut the cost of reaching orbit from around $10,000-$20,000 a kilogram to about $2,000 with its Falcon 9 rocket - "they have built a railroad to space."

From BBC ● Aug. 6, 2026

Evercore ISI analysts estimated recently that Falcon 9 payloads cost $2,700 a kilogram to send into orbit, while Starship should bring that down to $185 a kilogram.

From The Wall Street Journal ● Aug. 5, 2026

Expert groups commonly recommend around 1.0 to 1.2 grams of protein per kilogram of body weight per day for healthy older adults.

From Science Daily ● Jun. 6, 2026

I stop at the door and stare back, hoping when I return to check on the toxin, the LD 50 will be 0.000 nanograms per kilogram.

From "The Last Cuentista" by Donna Barba Higuera

During the experimental phase, the three lions received approximately 200 kilograms of carcasses.

From Science Daily ● Oct. 7, 2026

You squeeze the device as hard as you can for a few seconds and a needle gauge measures your strength in kilograms.

From The Wall Street Journal ● Oct. 1, 2026

Harmony’s average gold price in fiscal 2026 rose 35% to $3,811 a ounce, which more than offset a 3% fall in group gold production of 44,464 kilograms.

From The Wall Street Journal ● Aug. 27, 2026

When Lisa Rees took her first dose of weight-loss medication in April, she hoped she would end up losing a few kilograms.

From BBC ● Aug. 8, 2026

The Los Alamos lab, recently established under Oppenheimer’s leadership, tripled to 40 kilograms its estimate of the quantity of U-235 needed for a bomb.

From "Big Science" by Michael Hiltzik

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