Units of Measurement

Introduction
We live in a physical universe with physical matter, and a complete system of standardised units describing the physical quantities around us is required to allow us to measure and quantify the universe and its contents. Without a standard unit system, trade would be very difficult and science would be unable to build on previous results without using unwieldy fractions such as 1/47382 of a meter.

This book collects information on the units of measurement in use, defining them and comparing to other units in the same and other systems. For example, you may find a meter here, or a kilogram, or a nanosecond, or even a furlong.

Unit systems

 * /SI units/
 * /CGS units/
 * /Imperial units/

Unit by physical quantity described

 * /Length/
 * /Area/
 * /Volume/
 * /Mass/
 * /Time/
 * /Angle/
 * /Frequency/
 * /Temperature/
 * /Density/
 * /Velocity/
 * /Angular velocity/
 * /Acceleration/
 * /Angular acceleration/
 * /Force/
 * /Pressure/
 * /Energy/
 * /Power/
 * /Action/
 * /Entropy/
 * /Viscosity/
 * /Surface tension/
 * /Thermal conductivity/
 * /Amount of substance/
 * /vibration/