# Units and Conversions

The International System of Units (SI) contains seven BASE UNITS that each represent a different kind of physical quantity.

Length (Online Converter)

• SI unit: meter (m)
• The meter defined as "the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second."

Volume (Online Converter)

• SI unit: cubic meter ($$m^3$$)
• The cubic meter is defined as the volume of a cube with edges one meter in length. A liter is exactly 1/1000th of a cubic meter.

Mass (Online Converter)

• SI unit: kilogram (kg)
• The kilogram is defined as being equal to the mass of the International Prototype of the Kilogram (manufactured in 1799).

Pressure (Online Converter)

• SI unit: pascal (Pa)
• The pascal is a derived from other units

$1\, Pa = 1 \dfrac{kg}{m \cdot s^2}$

Temperature (Online Converter)

• SI unit: kelvin (K)
• The kelvin is defined as the fraction 1273.16 of the thermodynamic temperature of the triple point of water (exactly 0.01 °C).

Energy (Online Converter)

• SI unit: joule (J)
• The joule is derived from other units

$1 \, J = 1 \, kg \dfrac{m^2}{s^2}$