International System of Units

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What Does International System of Units Mean?

The International System of Units (SI) is considered the modern form of the metric system and is now the most widely used system of measurement in the world. It is used both in science and in everyday commerce. The standard was based on the meter-kilogram-second (MKS) system and was published in 1960 as a result of the initiative that started in 1948. It is part of the International System of Quantities.


Techopedia Explains International System of Units

The International System of Units consists of coherent systems of measurement built around 7 base units, 22 named and a number of unnamed coherent derived units, and a set of prefixes that serve as decimal-based multipliers.

It is declared as an evolving system, so there can be new units and prefixes created, and even unit definitions can be modified through an international agreement as the technology and precision of measurements improve.

All SI units can be expressed directly or in terms of standard multiples or fractional quantities by powers of 10 ranging from 10-24 to 1024.

The seven base SI units are as follows:

  • Meter
  • Kilogram
  • Second
  • Kelvin
  • Ampere
  • Candela
  • Mole

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Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.