Use this page to learn how to convert between pounds and kilograms. Type in your own numbers in the form to convert the units! You can do the reverse unit conversion from kg to pounds , or enter any two units below:. The pound abbreviation: lb is a unit of mass or weight in a number of different systems, including English units, Imperial units, and United States customary units. Its size can vary from system to system. The most commonly used pound today is the international avoirdupois pound.
The international avoirdupois pound is equal to exactly The definition of the international pound was agreed by the United States and countries of the Commonwealth of Nations in In the United Kingdom, the use of the international pound was implemented in the Weights and Measures Act An avoirdupois pound is equal to 16 avoirdupois ounces and to exactly 7, grains. The kilogram or kilogramme, symbol: kg is the SI base unit of mass.
It is currently defined based on the fixed numerical value of the Planck constant, h, which is equal to 6. Even though the definition of the kilogram was changed in , the actual size of the unit remained the same. The changes were intended to improve the definitions of SI base units, not to actually change how the units are used throughout the world.
SI is a system based on the meter-kilogram-second system of units rather than a centimeter-gram-second system. This is at least in part due to the inconsistencies and lack of coherence that can arise through use of centimeter-gram-second systems, such as those between the systems of electrostatic and electromagnetic units.
The kilogram was originally defined as the mass of one liter of water at its freezing point in , but was eventually re-defined, since measuring the mass of a volume of water was imprecise and cumbersome. A new definition of the kilogram was introduced in based on Planck's constant and changes to the definition of the second.
Prior to the current definition, the kilogram was defined as being equal to the mass of a physical prototype, a cylinder made of a platinum-iridium alloy, which was an imperfect measure. This is evidenced by the fact that the mass of the original prototype for the kilogram now weighs 50 micrograms less than other copies of the standard kilogram. Current use: As a base unit of SI, the kilogram is used globally in nearly all fields and applications, with the exception of countries like the United States, where the kilogram is used in many areas, at least to some extent such as science, industry, government, and the military but typically not in everyday applications.
From: pound To: kilogram.
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