SI Units

SI Base and Derived units with Prefixes

Basic SI Units, derived si units and Prefixes. Decimal multiples or fractions of SI units, The SI system has seven base units from which all other units are derived. engineering mindset

The SI units of measurement are based on seven quantities, other commonly used quantities are derived from these.

SI Base units:

Base Quantity Base Unit Base Symbol
Length Meter m
Time Second s
Mass Kilogram kg
Temperature Kelvin K
Electric current Ampere A
Luminous intensity Candela cd
Amount of substance Mole Mol

SI derived units:

Derived quantity Derived unit Derived symbol
Area square meter [m2]
Volume cubic meter [m3]
acceleration meter per second squared [m/s2]
Speed, velocity meter per second [m/s]
wave number reciprocal meter [m-1]
mass density kilogram per cubic meter [kg/m3]
specific volume cubic meter per kilogram v [kg/m3]
current density ampere per square meter [A/m2]
magnetic field strength ampere per meter [A/m]
amount of substance concentration mol per cubic meter [mol/m3]
luminance caldela per square meter [cd/m2]
mass fraction kilogram per kilogram [kg/kg]
Frequency Hertz f [Hz]
Force Newton N
Energy, Work Joule J
Electric charge Coulomb C
Power Watt W [J/s]
Potential difference volt V or U
Capacitance Farad F
Electrical resistance Ohm Ω
Magnetic flux Weber Wb [V.s]
Magnetic flux density Tesla T [Wb/m2]
Inductance Henry H
Pressure Pascal Pa [N/m2]
Radionuclide activity Becquerel Bq
Dynamic viscosity Pascal second µ [Pa·s]
Moment of force Newton meter [N·m]
Surface tension Newton per meter [N/m]
Angular velocity Radian per second [rad/s]
Angular acceleration Radian per second squared [rad/s2]
Heat flux density, irradiance Watt per square meter [W/m2]
Entropy Joule per kelvin S [J/K]
Specific heat capacity, specific entropy Joule per kilogram kelvin cp [J/(kg·K)]
Specific energy Joule per kilogram J/kg
Thermal conductivity Watt per meter kelvin K [W/(m·K)]
Energy density Joule per cubic meter [J/m3]
Electric field strength Volt per meter [V/m]
Electric charge density Coulomb per cubic meter [C/m3]
Electric flux density Coulomb per square meter [C/m2]
Molar energy Joule per mole [J/mol]
Molar entropy Joule per mole Kelvin [J/(mol·K)]
Absorbed dose rate Gray per second [Gy/s]
Radiant intensity Watt per steradian [W/sr]
Radiance Watt per square meter Steradian [W/(m2·sr)]
catalytic concentration katal per cubic meter [kat/m3]

SI Unit prefixes

Name Multiplier Prefix Power of 10
Tera 1,000,000,000,000 T 1 x 1012
Giga 1,000,000,000 G 1 x 109
Mega 1,000,000 M 1 x 106
Kilo 1,000 k 1 x 103
Unit 1
Milli 0.001 m 1 x 10-3
Micro 0.000,001 µ 1 x 10-6
Value-1 Value-2 η 1 x 10-9
Value-1 Value-2 ρ 1 x 10-12

SI Base units: Table as image for offline viewing


SI Unit prefixes: Table as image for offline viewing

SI Unit prefixes TABLE
SI Unit prefixes TABLE

SI derived units:Table as image for offline viewing

SI derived units TABLE
SI derived units TABLE


Please enter your comment!
Please enter your name here