List of physical quantities

Quick reference
	Ratio size
	related size
	extensive state variable
	intensive state variable
	Process variable
	Energy size
	Field size

This list shows all the important physical quantities  - the SI base quantities and quantities derived from them - in technology and natural sciences, sorted according to areas of knowledge.

The symbols used are largely based on the international standards or those specified by DIN 1304 for German-speaking countries. Several symbols are common for some physical quantities, as this quantity is used in different areas of application.

There are clear standards for correct use and the notation of sizes, units and values .

Physical constants are not listed in the table below.

SI base quantities and units

Base size	Formula symbol	Symbol for dimension	Base unit	Unit symbol
length	${\displaystyle l\,}$, , , , Etc. ${\displaystyle s\,}$ ${\displaystyle x\,}$ ${\displaystyle r\,}$	L.	meter	${\displaystyle \mathrm {m} \,}$
Dimensions	${\displaystyle m\,}$	M.	kilogram	${\displaystyle \mathrm {kg} \,}$
time	${\displaystyle t\,}$	T	second	${\displaystyle \mathrm {s} \,}$
electric current	${\displaystyle I\,}$	I.	amp	${\displaystyle \mathrm {A} \,}$
absolute temperature (also thermodynamic temperature )	${\displaystyle T\,}$	θ	Kelvin	${\displaystyle \mathrm {K} \,}$
Amount of substance	${\displaystyle n\,}$	N	Mole	${\displaystyle \mathrm {mol} \,}$
Light intensity	${\displaystyle I_{\mathrm {V} }\,}$	J	Candela	${\displaystyle \mathrm {cd} \,}$

geometry

Size type	Physical size	Formula symbol	Dimen.	SI unit	Other units	comment
flat angle	flat angle , angle of rotation	${\displaystyle \alpha ,\,\beta ,\,\gamma ,\,\ldots ,}$ ${\displaystyle \varphi ,\,\theta ,\,\ldots }$	1	Radian (rad)	Degree (°) Gon (gon, g ) arc minute (′)
Solid angle	Solid angle	${\displaystyle \Omega ,\,\omega }$	1	Steradian (sr)	Square degree ((°) ²)
length	length	${\displaystyle l\,}$	L.	Meter (m)	Ångström (Å) astronomical unit  (AU) light year (Lj, ly, lyr) parsec (pc) nautical mile (sm)
length	width	${\displaystyle b\,}$	L.	Meter (m)	Ångström (Å)
length	Height , depth	${\displaystyle h\,}$	L.	Meter (m)	Ångström (Å)
length	Thickness, layer thickness	${\displaystyle \sigma ,\,d}$	L.	Meter (m)	Ångström (Å)
length	Radius ( radius ), distance	${\displaystyle r\,}$	L.	Meter (m)	Ångström (Å) astronomical unit (AU) light year (Lj, ly, lyr) parsec (pc)
length	diameter	${\displaystyle d,\,D}$	L.	Meter (m)	Ångström (Å) astronomical unit (AU) light year (Lj, ly, lyr) parsec (pc)
length	Path length, curve length	${\displaystyle s\,}$	L.	Meter (m)	Ångström (Å) astronomical unit (AU) light year (Lj, ly, lyr) parsec (pc) nautical mile (sm)
surface	Area , surface	${\displaystyle A,\,S}$	L 2	Square meter (m 2 )	Ar (a) hectare (ha)
surface	Cross sectional area	${\displaystyle S,\,Q}$	L 2	Square meter (m 2 )	Barn (b)
volume	Volume , volume	${\displaystyle V\,}$	L 3	Cubic meter (m 3 )	Liter (l)

kinematics

Size type	Physical size	Formula symbol	dimension	SI unit	Other units	comment
time	Time, time span , duration	${\displaystyle t\,}$	T	Second (s)	Minute (min) hour (h) day (d) year (a)
time	Period duration	${\displaystyle T,\,{\tau }}$	T	Second (s)	Minute (min) hour (h) day (d) year (a)
time	Time constant	${\displaystyle {\tau },\,T}$	T	Second (s)
speed	speed	${\displaystyle v,\,u,\,w,\,c}$	LT −1	m · s −1	Kilometers per hour (km h −1 )
speed	Flow velocity	${\displaystyle \omega \,}$	LT −1	m · s −1	Kilometers per hour (km h −1 )
acceleration	acceleration	${\displaystyle a\,}$	LT −2	m · s −2
acceleration	local acceleration due to gravity	${\displaystyle g\,}$	LT −2	m · s −2	gal
shock	shock	${\displaystyle j\,}$	LT −3	m · s −3
frequency	Frequency , period frequency	${\displaystyle f,\,\nu }$	T −1	Hertz (Hz)	s −1
frequency	Speed , rotational frequency	${\displaystyle n,\,f_{\mathrm {rot} }}$	T −1	s −1	U · s −1
Angular frequency	Angular frequency , angular frequency	${\displaystyle \omega \,}$	T −1	rad · s −1
Angular velocity	Angular velocity	${\displaystyle \omega ,\,\Omega }$	T −1	rad · s −1
Angular acceleration	Angular acceleration	${\displaystyle \alpha \,}$	T −2	rad · s −2
length	wavelength	${\displaystyle \lambda \,}$	L.	Meter (m)	Ångström (Å)
viscosity	kinematic viscosity	${\displaystyle \nu \,}$	L 2 T -1	m 2 s −1	Stokes (St)

mechanics

Size type	Physical size	FZ	dimension	SI unit	Other units	comment
Dimensions	Dimensions	${\displaystyle m\,}$	M.	Kilogram (kg)	Gram (g) ton (t) metric carat (ct)
force	force	${\displaystyle F\,}$	MLT −2	Newton (N)	dyn (dyn) kilopond (kp)
force	Weight force	${\displaystyle F_{\mathrm {G} },\,G}$	MLT −2	Newton (N)	Dyn (dyn) kilopond (kp)
force	friction	${\displaystyle F_{\mathrm {R} }\,}$	MLT −2	Newton (N)	Dyn (dyn) kilopond (kp)
pulse	pulse	${\displaystyle p\,}$	MLT −1	N · s	kg m s −1
pulse	Impulse	${\displaystyle S,\,I}$	MLT −1	N · s	kg m s −1
Moment of inertia	Moment of inertia	${\displaystyle I,\,J,\,{\mathit {\Theta }}}$	ML 2	kg · m²
Torque	Torque ( moment of force )	${\displaystyle M\,}$	ML 2 T −2	Newton meter (Nm)	Dynmeter (dynm) Kilopondmeter (kpm)
Torque	Torsional , restraint moment , bending moment	${\displaystyle M_{\mathrm {T} },\,T;\,M}$	M L² T −2	Newton meter (Nm)
Angular momentum	Angular momentum , twist	${\displaystyle L\,}$	M L² T −1	kg · m² · s −1	J · s
effect	effect	${\displaystyle S\,}$	ML 2 T −1	kg · m² · s −1	J · s
energy	job	${\displaystyle W,\,E}$	M L² T −2	Joule (J)	Newton meter (Nm) Kilowatt hour (kWh) Electron volt (eV) Kilopond meter (kpm) Erg (erg) Calorie (cal)
energy	energy	${\displaystyle W,\,E}$	M L² T −2	Joule (J)	Newton meter (Nm) Kilowatt hour (kWh) Electron volt (eV) Kilopond meter (kpm) Erg (erg) Calorie (cal)
Energy density	volumetric energy density	${\displaystyle \rho ,\,w}$	ML −1 T −2	J m −3
Energy density	specific energy	${\displaystyle \rho ,\,w}$	L 2 T −2	J kg −1
power	power	${\displaystyle P\,}$	ML 2 T −3	Watt (W)	VA kpm s −1 horsepower (PS)
Power density	Intensity , area-related power density	${\displaystyle I,\,S,\,E,\,M,\,q,\,\psi }$	MT −3	W m −2
Power density	volumetric power density	${\displaystyle \phi }$	ML −1 T −3	W m −3
Power density	specific performance	${\displaystyle \rho ,\,w}$	L 2 T −3	W kg −1
coefficient	Efficiency	${\displaystyle \eta \,}$	1	one
Mass density	density	${\displaystyle \rho ,\,\rho _{\mathrm {m} }}$	M · L −3	kg m −3
Mass occupancy	Mass occupancy	${\displaystyle \rho _{\mathrm {A} }}$	M · L −2	kg m −2
specific volume	specific volume	${\displaystyle v\,}$	M −1 L 3	m 3 kg −1
specific weight	specific weight (specific gravity)	${\displaystyle \gamma \,}$	M · L −2 · T −2	kg m −2 s −2	N m −3
mechanical tension	pressure	${\displaystyle p\,}$	M · L −1 · T −2	Pascal  (Pa)	Bar  (bar) physical atmosphere  (atm) technical atmosphere  (at) Torr  (Torr) millimeter mercury column (mm Hg) meter water column  (mWS)
mechanical tension	absolute pressure	${\displaystyle p_{\mathrm {abs} }\,}$	ML −1 T −2	Pascal (Pa)	Nm −2 bar (bar)
mechanical tension	Air pressure	${\displaystyle p_{\mathrm {amb} }\,}$	ML −1 T −2	Pascal (Pa)	Nm −2 bar (bar)
mechanical tension	atmospheric pressure difference , overpressure	${\displaystyle p_{\mathrm {e} }\,}$	ML −1 T −2	Pascal (Pa)	N · m -2 bar (bar)
mechanical tension	Normal stress ( tensile or compressive stress )	${\displaystyle \sigma \,}$	ML −1 T −2	Pascal (Pa)	N · m -2 bar (bar)
mechanical tension	Shear stress	${\displaystyle \tau \,}$	ML −1 T −2	Pascal (Pa)	N · m -2 bar (bar)
module	modulus of elasticity	${\displaystyle E\,}$	ML −1 T −2	N m −2
module	Shear modulus	${\displaystyle G\,}$	ML −1 T −2	N m −2
module	Compression module	${\displaystyle K\,}$	ML −1 T −2	N m −2
Spring constant	Spring constant	${\displaystyle D,\,k,\,c}$	MT −2	N m −1
Compressibility	Compressibility	${\displaystyle \kappa ,\,\chi }$	MT −2	N m −1
coefficient	Elongation , relative change in length	${\displaystyle \mathrm {\epsilon \,} }$	1	one
coefficient	Push , shear	${\displaystyle \gamma \,}$	1	one
coefficient	Poisson's number	${\displaystyle \mu ,\,\nu }$	1	one
viscosity	dynamic viscosity	${\displaystyle \eta \,}$	ML −1 T −1	Pa · s	Poise (P)
viscosity	kinematic viscosity	${\displaystyle \nu \,}$	L 2 T −1	m 2 s −1	Stokes (St)
coefficient	Reynolds number	${\displaystyle Re\,}$	1	one
coefficient	Coefficient of friction	${\displaystyle \mu ,\,f}$	1	one
Volume flow	Volume flow	${\displaystyle Q\,}$	L 3 T −1	m 3 s −1
Mass flow	Mass flow	${\displaystyle q_{m}}$	MT −1	kg s −1

thermodynamics

Size type	Physical size	Formula symbol	dimension	SI unit	Other units	comment
temperature	absolute temperature	${\displaystyle T\,}$	Θ	Kelvin (K)
temperature	Temperature difference	${\displaystyle {\Delta T,\,\Delta \vartheta ,\,\Delta t}}$	Θ	Kelvin (K)	Degree Celsius (° C) Degree Fahrenheit (° F) Degree Rankine (° Ra) Degree (grd.)
temperature	Celsius temperature	${\displaystyle \vartheta ,\,t}$	Θ	Degrees Celsius (° C)	Kelvin (K)
energy	Heat , amount of heat	${\displaystyle Q\,}$	ML 2 T −2	Joule (J)
energy	inner energy	${\displaystyle U\,}$	ML 2 T −2	Joule (J)
energy	thermal energy	${\displaystyle E_{\mathrm {th} }\,}$	ML 2 T −2	Joule (J)
energy	chemical potential	${\displaystyle \mu \,}$	ML 2 T −2	Joule (J)
energy	Enthalpy	${\displaystyle H\,}$	ML 2 T −2	Joule (J)
power	Heat flow	${\displaystyle {\mathit {\Phi }}_{\mathrm {th} },\,{\mathit {\Phi }},\,{\dot {Q}}}$	ML 2 T −3	Watt (W)	J · s −1
Power density	Heat flux density	${\displaystyle {q},\,{\dot {q}}}$	MT −3	W m −2
entropy	entropy	${\displaystyle S\,}$	ML 2 T −2 Θ −1	J · K −1
Heat capacity	Heat capacity	${\displaystyle C_{\mathrm {th} },\,C}$	ML 2 T −2 Θ −1	J · K −1
specific heat capacity	specific heat capacity	${\displaystyle c\,}$	L 2 T −2 Θ −1	J K −1 kg −1
Temperature coefficient	Coefficient of linear expansion	${\displaystyle {\alpha }_{1}\,}$	Θ −1	K −1
Temperature coefficient	Volume expansion coefficient	${\displaystyle {\alpha }_{v},\,\gamma }$	Θ −1	K −1
Thermal conductivity	Thermal conductivity	${\displaystyle {\lambda }\,}$	MLT −3 Θ −1	W K −1 m −1
Temperature coefficient	Heat transfer coefficient	${\displaystyle \alpha ,\,h}$	MT −3 Θ −1	W K −1 m −2
Temperature coefficient	Heat transfer coefficient	${\displaystyle U\,}$	MT −3 Θ −1	W K −1 m −2
Thermal resistance	Thermal resistance	${\displaystyle R\,}$	M −1 T 3 Θ	m 2 W K −1
Thermal diffusivity	Thermal diffusivity	${\displaystyle a\,}$	L 2 T −1	m 2 s −1

Electrodynamics

Size type	Physical size	Formula symbol	dimension	SI unit	Other units	comment
el. amperage	electric current	${\displaystyle I}$	I.	Ampere (A)	Biot (bi)
el. current density	electric current density	${\displaystyle J,j,S}$	I · L −2	A m −2
el. charge	electric charge	${\displaystyle Q}$	IT	Coulomb (C)	A s Franklin (Fr)
el. voltage	electrical voltage , electrical potential difference	${\displaystyle U}$	ML 2 T −3 I −1	Volt (V)	W A −1 J C −1
el. potential	electrical potential	${\displaystyle \varphi }$	ML 2 T −3 I −1	Volt (V)	W A −1 J C −1
el. resistance	ohmic resistance , effective resistance	${\displaystyle R}$	ML 2 T −3 I −2	Ohm ( ) ${\displaystyle \Omega }$	V · A −1
el. resistance	Reactance	${\displaystyle X}$	ML 2 T −3 I −2	Ohm ( ) ${\displaystyle \Omega }$	V · A −1
el. resistance	Impedance , impedance	${\displaystyle Z}$	ML 2 T −3 I −2	Ohm ( ) ${\displaystyle \Omega }$	V · A −1
specific electrical resistance	specific electrical resistance	${\displaystyle \varrho }$	ML 3 T −3 I −2	Ω m
el. conductance	electrical conductance , effective conductance	${\displaystyle G}$	M −1 L −2 T 3 I 2	Siemens (S)	Ω −1 , A · V −1
el. conductance	Susceptance	${\displaystyle B}$	M −1 L −2 T 3 I 2	Siemens (S)	Ω −1 , A · V −1
el. conductance	Admittance , admittance	${\displaystyle Y}$	M −1 L −2 T 3 I 2	Siemens (S)	Ω −1 , A · V −1
specific electrical conductance	specific electrical conductance	${\displaystyle \sigma }$	M −1 L −3 T 3 I 2	S m −1
force	Lorentz force	${\displaystyle F_{\mathrm {L} }}$	MLT −2	Newton (N)	Dyn (dyn) kilopond (kp)
el. field strength	electric field strength	${\displaystyle E}$	MLT −3 I −1	V m −1	N · C −1
el. river	electric flow	${\displaystyle \Psi }$	IT	C.
el. flux density	electrical flux density (electrical excitation), displacement density	${\displaystyle D}$	IL −2 T	C m −2
el. polarization	polarization	${\displaystyle P}$	IL −2 T	C m −2
el. polarizability	Polarizability	${\displaystyle \alpha }$	M −1 I 2 T 4	C m 2 V −1
magnet. Flux density	magnetic flux density , magnetic induction	${\displaystyle B}$	MT −2 I −1	Tesla (T)	Gauss (G) γ
magnet. Flux density	magnetic polarization	${\displaystyle J\,}$	MT −2 I −1	Tesla (T)	Gauss (G) γ
magnet. Field strength	magnetic field strength , magnetic excitation	${\displaystyle H}$	L −1 I	A m −1	Oersted (Oe)
magnetization	magnetization	${\displaystyle M}$	L −1 I	A m −1
magnet. flow	Magnetic river	${\displaystyle {\mathit {\Phi }}}$	ML 2 T −2 I −1	Weber (Wb)	Vs Maxwell (M)
magnetic moment	magnetic moment	${\displaystyle \mu }$	L 2 I	A m 2
el. capacity	electrical capacitance	${\displaystyle C}$	M −1 L −2 T 4 I 2	Farad (F)	C · V −1 , A · s · V −1
Elasticity	Elasticity	${\displaystyle S}$	ML 2 T −4 I −2	F −1
Inductance	Inductance	${\displaystyle L}$	ML 2 T −2 I −2	Henry (H)	Wb · A −1
Permittivity	Permittivity	${\displaystyle \epsilon }$	M −1 L −3 T 4 I 2	F m −1
permeability	Magnetic permeability	${\displaystyle \mu }$	MLT −2 I −2	H m −1
power	Apparent power	${\displaystyle S}$	ML 2 T −3	Volt amperes (VA)
power	Real power	${\displaystyle P}$	ML 2 T −3	Watt (W)
power	Reactive power	${\displaystyle Q}$	ML 2 T −3	Var (var)
Charge density	Line charge density	${\displaystyle \lambda }$	ITL −1	C m −1
Charge density	Surface charge density	${\displaystyle \sigma }$	ITL −2	C m −2
Charge density	Space charge density	${\displaystyle \rho }$	ITL −3	C m −3
magnet. potential	magnetic potential	${\displaystyle \psi }$	I.	A.
magnet. potential	magnetic potential field	${\displaystyle A}$	I.	A.
magnet. tension	magnetic flooding	${\displaystyle \Theta }$	I.	A.	AW, Aw Gilbert (Gb)
magnet. flow	magnetic interlinking flux	${\displaystyle \Psi }$	ML 2 T −2 I −1	Weber (Wb)	V s Maxwell (M)
Susceptibility	electrical susceptibility	${\displaystyle \chi _{e}}$	1	1
Susceptibility	magnetic susceptibility	${\displaystyle \chi ,\chi _{\mathrm {v} },\chi _{\mathrm {m} },\chi _{\mathrm {mag} }}$	1	1
molar susceptibility	molar susceptibility	${\displaystyle \chi _{\mathrm {mol} }}$	L 3 N −1	m 3 · mol -1
Mass susceptibility	Mass susceptibility	${\displaystyle \chi _{\mathrm {mass} },\chi _{\mathrm {g} },\chi _{\mathrm {m} }}$	L 3 M −1	m 3 kg −1

Atomic and Molecular

Size type	Physical size	Formula symbol	dimension	SI unit	Other units	comment
Amount of substance	Amount of substance	n	N	Mole (mol)	Val (val)
molar volume	molar volume	${\displaystyle V_{\mathrm {m} }\,}$	L 3 N −1	m 3 mol −1
molar mass	molar mass	${\displaystyle M\,}$	MN −1	g mol −1
relative mass	relative atomic mass	${\displaystyle A_{\mathrm {r} }\,}$	1	one
relative mass	relative molecular weight	${\displaystyle M_{\mathrm {r} }\,}$	1	one
Value	Charge number of an ion , valence of a substance B	${\displaystyle z_{\mathrm {B} }\,}$	1	one

Nuclear physics

Size type	Physical size	Formula symbol	dimension	SI unit	Other units	comment
activity	activity	${\displaystyle A\,}$	T −1	Becquerel (Bq)	Curie (unit) (Ci) Stat (St) Eman (eman) Mache unit (ME)
specific activity	specific activity	${\displaystyle A\,}$	M −1 T −1	Bq kg −1
time	Half-life	${\displaystyle T_{\frac {1}{2}}\,}$	T	Second (s)
time	lifespan	${\displaystyle \tau \,}$	T	Second (s)
reciprocal time	Decay constant	${\displaystyle \lambda \,}$	T −1	s −1
specific energy	Absorbed dose	${\displaystyle D\,}$	L 2 T −2	Gray (Gy)	J kg −1 wheel (rad)
Equivalent dose	Equivalent dose	${\displaystyle H\,}$	L 2 T −2	Sievert (Sv)	J kg −1 Rem (rem)
Ion dose	Ion dose	${\displaystyle J\,}$	M −1 IT	A s kg −1	X-ray (R)
surface	Cross section	${\displaystyle \sigma \,}$	L 2	Square meter (m 2 )	Barn b

Radiometry

Size type	Physical size	Formula symbol	dimension	SI unit	Other units	comment
Power density	Radiation intensity (radiation intensity)	${\displaystyle I\,}$	ML 2 T −3	W sr −1		english radiant intensity
power	Radiation flux	${\displaystyle {\mathit {\Phi }}\,}$	ML 2 T −3	Watt (W)		engl. radiant flux , radiant power
energy	Radiant energy (amount of radiation)	${\displaystyle Q\,,\,E}$	ML 2 T −2	Joule (J)		engl. radiant energy
Radiance	Radiance	${\displaystyle L\,}$	MT −3	W m −2 sr −1		engl. radiance
Power density	Irradiance	${\displaystyle E\,,\,I}$	MT −3	W m −2		engl. irradiance
Power density	specific charisma	${\displaystyle M\,}$	MT −3	W m −2		engl. radiant exitance , radiant emittance
Energy density	Irradiation	${\displaystyle H\,}$	MT −2	J m −2		engl. radiant exposure

Photometry and optics

Size type	Physical size	Formula symbol	dimension	SI unit	Other units	comment
Light intensity	Light intensity	${\displaystyle I_{\mathrm {v} }\,}$	J	Candela  (cd)	Hefner candle  (HK)	english luminous intensity
Luminous flux	Luminous flux	${\displaystyle {\mathit {\Phi }}_{\mathrm {v} }\,}$, , ${\displaystyle {\mathit {F\,}}}$ ${\displaystyle {\mathit {P\,}}}$	J	Lumen  (lm)	cd sr	engl. luminous flux , luminous power
Light output	Light output	${\displaystyle \eta \,}$, ${\displaystyle \rho \,}$	M −1 L −2 T 3 J	lm · W −1		, engl. luminous efficacy
Amount of light	Amount of light	${\displaystyle Q_{\mathrm {v} }\,}$	TJ	Lumen second  (lm s)	cd sr s	engl. luminous energy
Luminance	Luminance	${\displaystyle L_{\mathrm {v} }\,}$	L −2 J	cd · m -2	Stilb  (sb), Apostilb  (asb), Lambert  (la), Blondel	, engl. luminance
Illuminance	Illuminance	${\displaystyle E_{\mathrm {v} }\,}$	L −2 J	Lux  (lx)	lm m −2 , Nox  (nx), Phot  (ph)	, engl. illuminance
specific light emission	specific light emission	${\displaystyle M_{\mathrm {v} }\,}$	L −2 J	lm m −2		engl. luminous emittance
exposure	exposure	${\displaystyle H_{\mathrm {v} }\,}$	L −2 TJ	Lux second  (lx s)		engl. luminous exposure
length	Focal length	${\displaystyle f\,}$	L.	Meter (m)		engl. focal length
reciprocal length	Refractive index , refractive power	${\displaystyle D\,}$	L −1	m −1	Diopter  (dpt)	engl. diopter , dioptre

Legend

1. ↑ ^{a b c d e f g h i j k} ratio
2. ↑ ^{a b c d e f g h i j k l m n o p q r s} related size
3. ↑ ^{a b c d e f g h i} extensive state variable
4. ↑ ^{a b c d e f g h i} intensive state variable
5. ↑ ^{a b c} process variable
6. ↑ ^{a b c d e f g h i j k l m n o} energy quantity
7. ↑ ^{a b c d e f g h i j k l m n o p q r s t u} field size
8. ↑ ^{a b} pseudo vector
9. ↑ Conservation size with regard to the homogeneity of the space
10. ↑ Conservation quantity with regard to the isotropy of space
11. ↑ Conservation size with regard to C-symmetry