Formula symbols of electrical engineering and electroacoustics
International System of Units (SI) in alphabetical order
Learn the metric system, the international decimalised system of measurement

Formula symbol Physical quantity Units Symbol of unit Remarks
B magnetic field, magnetic
flux density, induction
tesla = weber per
square metre
T
 T = Wb = V·s m2 m2
C electric capacitance farad F F = C/V = A·s/V = s/Ω
D electric flux density coulomb per square meter C/m2
E electric field strength volt per meter V/m
EV illuminance and
luminous emittance
lux Ix Ix = Im/m2
G electric conductance siemens S S = 1/Ω
H magnetic field strength ampere per meter A/m
I electric current ampere A
IV luminous intensity candela cd
J current density ampere per square meter A/m2
L inductance henry H H = Wb/A = V·s/A = Ω·s
LV luminance candela per square meter cd/m2
Θ magnetomotive force ampere-turn A
Φ magnetic flux weber Wb voltsecond V·s = Wb
ΦV luminous flux lumen Im
ρ (rho) electrical resistivity ohm times meter
ohm times square millimeter
divided by meter
Ω · m
Ω · mm2/m

P power watt, joule per second,
newtonmeter per second
W, J/s, Nm/s P = W / t
Q electric charge coulomb C amperesecond A·s = C
R electric resistance DC ohm Ω Ω = V/A
T period second s T=1 / f
T temperature Kelvin K 0 K = −273,15 °C
V electric voltage,
electric potential difference

volt V V = W/A
W work W = energy E wattsecond, Joule,
newtonmeter
Ws, J, Nm W = P × t
Z electric impedance AC ohm Ω Ω = V/A

Units of measurement of electrical engineering and electroacoustics
International System of Units (SI) in alphabetical order

Symbol of unit Physical quantity Formula symbol Units Remarks
A electric current I ampere
Ampere-turn magnetomotive force Θ ampere
A/m magnetic field strength H ampere per meter
A/m2 current density J ampere per square meter
C electric charge Q coulomb amperesecond A·s = C
C/m2 electric flux density D coulomb per square meter
cd luminous intensity IV candela
cd/m2 luminance LV candela per square meter
F electric capacity C farad F = A·s/V = s/Ω
H inductance L henry H = Wb/A = Vs/A = Ω·s
Ix illuminance and
luminous emittance
EV lux Ix = Im/m2
K temperature T Kelvin 0 K = −273,15 °C
Ω electric resistance, impedance R ohm Ω = V/A
Ω · m
Ω · mm2/m
electrical resistivity ρ (rho) ohm times square millimeter
divided by meter

S electric conductance G siemens S = 1/Ω
T magnetic field, magnetic
flux density, induction
B tesla
 T = Wb = V·s m2 m2
V electric voltage, V = P/A
electric potential difference
V volt V = W/A
V/m electric field strength E volt per meter
W power P = W / t  P watt W = J/s = Nm/s
Wb magnetic flux Φ weber voltsecond V·s = Wb
Ws work W = energy W = P × t W wattsecond Ws = J = Nm

SI Derived Units / Abgeleitete SI-Einheiten

English / German Frequency / Frequenz
hertz: Hz = 1/s

Force / Kraft
newton: N = m kg/s2
Pressure, stress / Druck, mechanische Spannung
pascal: Pa = N/m2= kg/m s2
Energy, work, quantity of heat / Energie, Arbeit, Wärmemenge
joule: J = N m = m2kg/s2
watt: W = J/s = m2kg/s3
Quantity of electricity, electric charge / elektrische Ladung
coulomb: C = s A
Electric potential / elektrische Spannung
volt: V = W/A = m2kg/s3 A
Capacitance / Kapazität
farad: F = C/V = s4A2/m2 kg
Electric resistance / elektrischer Widerstand
ohm: Ω = V/A = m2kg/s3 A2
Conductance / elektrische Leitfähigkeit
siemens: S = A/V = s3A2/m2 kg
Magnetic flux / magnetischer Fluss
weber: Wb = V s = m2kg/s2 A
Magnetic flux density, magnetic induction / Magnetische Induktion
tesla: T = Wb/m2 = kg/s2 A
Inductance / Induktivität
henry: H = Wb/A = m2kg/s2 A2
Luminous flux / Lichtstrom
lumen: lm = cd sr
Illuminance / Beleuchtungsstärke
lux: lx = lm/m2 = cd sr/m2
becquerel: Bq = 1/s
Absorbed dose / Absorbierte Strahlendosis
gray: Gy = J/kg = m2/s2
Dynamic viscosity / Dynamische Viskosität
pascal second: Pa s = kg/m s
Moment of force / Drehmoment
meter newton: N m = m2 kg/s2
Surface tension / Oberflächenspannung
newton per meter: N/m = kg/s2
Heat flux density, irradiance / Wärmeflussdichte
watt per squaremeter: W/m2 = kg/s3
Heat capacity, entropy / Wärmekapazität,Entropie
joule per kelvin: J/K = m2 kg/s2 K
Specific heat capacity, specific entropy /Spez. Wärmekapazität, spez. Entropie
joule per kilogram kelvin: J/kg K = m2/s2 K
Specific energy / Spezifische Energie
joule per kilogram: J/kg = m2/s2
Thermal conductivity / Thermische Leitfähigkeit
watt per meterkelvin: W/m K = m kg/s3 K
Energy density / Energiedichte
joule per cubicmeter: J/m3 = kg/m s2
Electric field strength / Elektrische Feldstärke
volt per meter: V/m = m kg/s3 A
Electric charge density / Elektrische Ladungsdichte
coulomb per cubicmeter: C/m3 = s A/m3
Electric displacement, electric flux density /Elektrische Flussdichte
coulomb per squaremeter: C/m2 = s A/m2
Permittivity / Influenz
farad per meter: F/m = s4 A2/m3 kg
Permeability / Permeabilität
henry per meter: H/m = m kg/s2 A2
Molar energy / Molare Energie
joule per mole: J/mol = m2 kg/s2 mol
Molar entropy, molar heat capacity / Molare Entropie, molare Wärmekapazität
joule per mole kelvin: J/mol K = m2 kg/s2 K mol
coulomb per kilogram: C/kg = s A/kg
Absorbed dose rate / Absorbierte Dosisrate
gray per second: Gy/s = m2/s3

### cgs Units / cgs-Einheiten

erg
1erg = 10−7 J
dyne
1 dyn = 10−5 N
poise
1 P = 1 dyn s/cm2 = 0.1 Pa s
stokes
1 St = 1 cm2/s = 10−4 m2/s
gauss
1G = 10−4 T
oersted
1Oe = (1000/(4π)) A/m
maxwell
1Mx = 10−8  Wb
stilb
1sb = 1 cd/cm2  = 104 cd/m2
phot
1ph = 104 lx