Electrical Units

Electrical & electronic units of electric current, voltage, power, resistance, capacitance, inductance, electric charge, electric field, magnetic flux, frequency:

• Electrical & electronic units table
• Units prefix table
• Units definitions

Electrical & electronic units table

Unit Name	Unit Symbol	Quantity
Ampere (amp)	A	Electric current (I)
Volt	V	Voltage (V, E) Electromotive force (E) Electric potential (φ)
Ohm	Ω	Resistance (R) Impedance (Z)
Watt	W	Electric power (P)
dBm	dBm	Electric power (P)
Volt-Ampere-Reactive	VAR	Reactive power (Q)
Volt-Ampere	VA	Apparent power (S)
Farad	F	Capacitance (C)
Henry	H	Inductance (L)
siemens / mho	S	Conductance (G) Admittance (Y)
Coulomb	C	Electric charge (Q)
Ampere-hour	A·h	Electric charge (Q)
Joule	J	Energy (E)
Kilowatt-hour	kWh	Energy (E)
Ohm-meter	Ω∙m	Resistivity (ρ)
siemens per meter	S/m	Conductivity (σ)
Volts per meter	V/m	Electric field (E)
Newtons per coulomb	N/C	Electric field (E)
Volt-meters	V·m	Electric flux (Φe)
Tesla	T	Magnetic field (B)
Gauss	G	Magnetic field (B)
Weber	Wb	Magnetic flux (Φm)
Hertz	Hz	Frequency (f)
Seconds	s	Time (t)
Meter / metre	m	Length (l)
Square-meter	m2	Area (A)

 

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Units prefix table

Prefix	Prefix Symbol	Prefix factor	Example
pico	p	10-12	1pF = 10-12F
nano	n	10-9	1nF = 10-9F
micro	μ	10-6	1μA = 10-6A
milli	m	10-3	1mA = 10-3A
kilo	K	10 3	1KΩ = 1000Ω
mega	M	10 6	1MHz = 106Hz
giga	G	10 9	1GHz = 109Hz

 

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Electrical units definitions

Volt (V)

Volt is the electrical unit of voltage.

One volt is the energy of 1 joule that is consumed when electric charge of 1 coulomb flows in the circuit.

1V = 1J / 1C

Ampere (A)

Ampere is the electrical unit of electrical current. It measures the amount of electrical charge that flows in an electrical circuit per 1 second.

1A = 1C / 1s

Ohm (Ω)

Ohm is the electrical unit of resistance.

1Ω = 1V / 1A

Watt (W)

Watt is the electrical unit of electric power. It measures the rate of consumed energy.

1W = 1J / 1s

1W = 1V · 1A

dBm

dBm is a unit of electric power, measured in dB-milliwatts.

1dBm = 10 · log₁₀(1.2589mW / 1mW)

Farad (F)

Farad is the unit of capacitance. It represents the amount of electric charge in coulombs that is stored per 1 volt.

1F = 1C / 1V

Henry (H)

Henry is the unit of inductance.

1H = 1Wb / 1A

siemens (S)

siemens is the unit of conductance, which is the opposite of resistance.

1S = 1 / 1Ω

Coulomb (C)

Coulomb is the unit of electric charge.

1C = 6.238792×10¹⁸ electron charges

Ampere-hour (Ah)

Ampere-hour is a unit of electric charge.

One ampere-hour is the electric charge that flow in electrical circuit, when a current of 1 ampere is applied for 1 hour.

1Ah = 1A · 1hour

One ampere-hour is equal to 3600 coulombs.

1Ah = 3600C

Tesla (T)

Tesla is the unit of magnetic field.

1T = 1Wb / 1m²

Weber (Wb)

Weber is the unit of magnetic flux.

1Wb = 1V · 1s

Joule (J)

Joule is the unit of energy.

1J = 1 kg · 1(m / s)²

Kilowatt-hour (kWh)

Kilowatt-hour is a unit of energy.

1kWh = 1000W · 1h

Hertz (Hz)

Hertz is the unit of frequency. It measures the number of cycles per second.

1 Hz = 1 cycles / s

 

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See also

• Kilowatt (kW)
• Kilowatt-hour (kWh)
• Watt
• Decibel
• dBm
• Volt
• Ampere (amp)
• Ohm
• Power conversion
• Electrical symbols