This table shows, from the International System of Units, base and derived physical units, their shorthand symbols, and equivalent units in other unit systems. Many of the terms in the table are defined in this topic.
BASE UNITS
|
Quantity or phenomenon (and symbol) |
Standard International unit (and symbol) |
Alternate units (and symbols) |
|
displacement (d) |
meter (m) |
centimeter (cm) foot (ft) |
|
mass (m) weight (w) |
kilogram (kg) |
gram (g) pound (lb) |
|
time (t) |
second (s) |
hour (hr) mean solar day (dy) synodic year (yr) |
|
current (I) |
ampere (A) |
statampere (statA) abampere (abA) |
|
temperature (T) |
kelvin (°K or K) |
degree Celsius (°C or C) degree Fahrenheit (°F or F) degree Rankine (°R or R) |
|
amount of substance (N) |
mole (mol) |
— |
|
luminous intensity (B or L) |
candela (cd) |
— |
DERIVED UNITS
|
Quantity or phenomenon (and symbol) |
Standard International unit (and symbol) |
Alternate units (and symbols) |
|
area (A) |
meter squared (m2) |
centimeter squared (cm2) circular mil foot squared (ft2) |
|
volume (V) |
meter cubed (m3) |
centimeter cubed (cm3) foot cubed (ft3) |
|
material density (D) |
kilogram per meter cubed (kg/m3 or kg • m-3) |
gram per centimeter cubed (g/cm3 or g • cm-3) |
|
specific volume |
meter cubed per kilogram (m3/kg or m3 • kg-1) |
centimeter cubed per gram (cm3/g or cm3 • g-1) |
|
amount of substance concentration |
mole per meter cubed (mol/m3 or mol • m-3) |
— |
|
force (F or F) |
newton (N) |
dyne (dyn) |
|
pressure stress |
pascal (Pa) |
dyne per centimeter squared (dyn/cm2 or dyn • cm-2) |
|
speed (s) velocity (v or v) |
meter per second (m/s or m • s-1) |
centimeter per second (cm/s or cm • s-1) |
|
acceleration (a or a) |
meter per second squared (m/s2 or m • s-2) |
centimeter per second squared (cm / s2 or cm • s-2) gravity (g) |
|
current density |
ampere per meter squared (A/m2 or A • m-2) |
ampere per centimeter squared (A / cm2 or A • cm-2) |
|
electromotive force (emf) Voltage (V or E) |
volt (V) |
statvolt (statV) abvolt (abV) |
|
resistance (R) |
ohm |
statohm (stat^) abohm (ab^) |
|
conductance (G) |
siemens (S) |
statsiemens (statS) absiemens (abS) |
|
electric field strength (E) |
volt per meter (V/m or V • m-1) |
microvolt per meter (pV/m or pV • m-1) |
DERIVED UNITS
|
Quantity or phenomenon (and symbol) |
Standard International unit (and symbol) |
Alternate units (and symbols) |
|
electric flux density |
coulomb per meter squared (C/m2 or C • m-2) |
— |
|
electric charge density |
coulomb per meter cubed (C/m3 or C • m-3) |
— |
|
permittivity(e) |
farad per meter (F/m or F • m-1) |
picofarad per meter (pF/m or pF • m-1) |
|
power (P) |
watt (W) |
horsepower (hp) statwatt (statW) abwatt (abW) |
|
energy (E) |
joule (J) |
erg (erg) watt hour (Wh) kilowatt hour (kWh) |
|
magnetomotive force (M or mmf) |
ampere-turn (AT) |
gilbert (G) |
|
charge quantity (Q) |
coulomb (C) |
statcoulomb (statC) abcoulomb (abC) faraday |
|
capacitance (C) |
farad (F) |
statfarad (statF) abfarad (abF) |
|
inductance (L) |
henry (H) |
stathenry (statH) abhenry (abH) |
|
magnetic flux (O) |
weber (Wb) |
maxwell (Mx) |
|
magnetic flux density |
tesla (T) |
gauss (G) |
|
magnetic field strength (H) |
ampere per meter (A/m or A • m-1) |
oersted (Oe) |
|
permeability (p) |
henry per meter (H/m or H • m-1) |
microhenry per meter (pH/m or pH • m-1) |
|
electromagnetic field strength |
watt per meter squared (W/m2 or W • m-2) |
microwatt per meter squared (pW/m2 or pW • m-2) |
|
radiant intensity |
watt per steradian (W/sr or W • sr-1) |
lumen (lm) |
|
luminance |
candela per meter squared (cd/m2 or cd • m-2) |
candela per centimeter squared (cd/cm2 or cd • cm-2) |
|
luminous flux |
lumen (lm) |
watt per steradian (W/sr or W • sr-1) |
|
illuminance |
lux (lx) |
watt per meter squared (W/m2 or W • m-2) |
|
plane angular measure |
radian (rad) |
degree (deg or °) |
|
solid angular measure |
steradian (sr) |
— |
|
angular speed (ra) angular velocity (ra) |
radian per second (rad/s or rad • s-1) |
degree per second (deg/s or deg • s-1) |
|
angular acceleration (a or a) |
radian per second squared (rad/s2 or rad • s-2) |
degree per second squared (deg/s or deg • s- ) |
|
ionizing radiation |
becquerel (Bq) |
curie (cu) |
|
absorbed ionizing radiation dose |
gray (Gy) |
rad (rad) |
|
frequency (f or v) |
hertz (Hz) |
kilohertz (kHz) megahertz (MHz) gigahertz (GHz) terahertz (THz) |
DERIVED UNITS
|
Quantity or phenomenon (and symbol) |
Standard International unit (and symbol) |
Alternate units (and symbols) |
|
wavelength (X) |
meter (m) |
centimeter (cm) millimeter (mm) nanometer (nm) Angstrom (A) |
|
wave number |
reciprocal meter (m-1) |
— |
|
data quantity |
bit (b) byte (B) |
kilobit (kb) megabit (Mb) gigabit (Gb) kilobyte (KB) megabyte (MB) gigabyte (GB) |
|
data speed bandwidth |
bit per second (bps) |
kilobit per second (kbps) megabit per second (Mbps) gigabit per second (Gbps) character per second (cps) |
