kilogram

noun

ki·​lo·​gram ˈki-lə-ˌgram  ˈkē-lə- 

1

: the base unit of mass in the International System of Units that is defined by setting the fixed numerical value of Planck's constant to 6.62607015 x 10^–34 joule seconds see Metric System Table

2

: a unit of force or weight equal to the weight of a kilogram mass under a gravitational attraction equal to that of the earth

Did you know?

The original concept of the kilogram, as the mass of a cubic decimeter of water (a bit more than a quart), was adopted as the base unit of mass by the new revolutionary government of France in 1793. In 1875, in the Treaty of the Meter, 17 countries, including the U.S., adopted the French kilogram as an international standard. In 1889 a new international standard for the kilogram, a metal bar made of platinum iridium, was agreed to; President Benjamin Harrison officially received the 1-kilogram cylinder for the U.S. in 1890. But no one uses that bar very often; for all practical purposes, a kilogram equals 2.2 pounds.

Examples of kilogram in a Sentence

Recent Examples on the Web

Coal produces about 211 pounds (96 kilograms) of heat-trapping carbon dioxide per million BTUs of energy produced, compared to natural gas which produces about 117 pounds (53 kilograms) and gasoline which is about 156 pounds (71 kilograms), according to the U.S. Energy Information Administration. —Seth Borenstein, Fortune, 4 Dec. 2023

For every 100 kilowatts of peak power, an EV motor uses 1.2 kilograms of neodymium-iron-boron permanent magnets on average, according to Adamas Intelligence. —IEEE Spectrum, 15 Nov. 2023

The spaceplane's return cargo capacity is about 4,000 pounds (1,850 kilograms), and the expendable Shooting Star cargo module, which will be jettisoned at the end of the mission to burn up in the atmosphere, can dispose of several tons of trash from the space station. —Stephen Clark, Ars Technica, 1 Nov. 2023

The excess fleece removed from Sugar weighed 12.6 kilograms — or a little under 28 lbs. — per the rescue. —Bailey Richards, Peoplemag, 1 Nov. 2023

In all, people across the world throw out roughly 9 billion kilograms (19.8 billion pounds) of e-waste commonly not recognized as such by consumers. —Andrew Paul, Popular Science, 12 Oct. 2023

Photos shared by the forestry ministry showed the newborn calf, weighing about 27 kilograms (60 pounds), covered in black hair and looking bright-eyed next to her mother. —Heather Chen, CNN, 3 Oct. 2023

Iridium’s biggest downsides are its scarcity and difficulty to obtain; only 7,000 kilograms are produced each year. —IEEE Spectrum, 30 Oct. 2023

The Japan Sumo Association announced in late September that potential sumo wrestlers would no longer have to meet the minimum height requirements of 167 centimeters (about 5'6) and weight requirements of 67 kilograms (about 147 pounds). —Christine Rousselle, Fox News, 20 Oct. 2023

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Word History

Etymology

French kilogramme, from kilo- + gramme gram

First Known Use

1797, in the meaning defined at sense 1

Phrases Containing kilogram

• kilogram-meter
• meter-kilogram-second

• kilogram-meter
• meter-kilogram-second

Kids Definition

kilogram

noun

ki·​lo·​gram ˈkē-lə-ˌgram  ˈkil-ə- 

1

: the basic unit of mass in the metric system that has been accepted by international agreement and is nearly equal to the mass of 1000 cubic centimeters of water at its highest density see metric system

2

: the weight of a kilogram mass on the earth

he weighs 80 kilograms

see metric system

Medical Definition

kilogram

noun

ki·​lo·​gram

variants or chiefly British kilogramme

ˈkil-ə-ˌgram  ˈkē-lə- 

1

: the base unit of mass in the International System of Units that is equal to the mass of a prototype agreed upon by international convention and that is nearly equal to the mass of 1000 cubic centimeters of water at the temperature of its maximum density

2

: a unit of force equal to the weight of a kilogram mass under a gravitational attraction equal to that of the earth