Examples for

SI Units

SI, or Système international, units are an internationally standardized set of metric units built up from base units, prefixes and derived units. With Wolfram|Alpha, you can perform unit conversions using the base SI units, consisting of the meter for length, kilogram for mass, second for time, ampere for electric current, kelvin for temperature, mole for an amount of a substance and candela for luminous intensity, or derived SI units, such as the joule for energy, volt for electric potential difference and many others. You can also do calculations using compound units, such as meters per second for speed and kilograms per cubic meter for mass density, or explore the names and values of the set of prefixes defined in the SI system.
SI Units

Convert between SI and other units and obtain additional information about them.

Discover information about and convert from SI units:

centimeter
meters/second
amperes

Convert SI quantities to other units:

3 meters
1000 seconds

Convert quantities to or from SI units:

convert 55 mph to SI
110 km/h to miles per hour

Find standard SI units used to measure a particular physical quantity:

momentum
units of force
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SI Prefixes

Explore SI prefix names and values.

Return a list of SI prefixes:

si prefixes

Find information (including the SI prefix name) for a given multiplier:

1/1000
10^-9
10^12
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