Electrical Units

Electrical units table | Units prefix table | Electrical units definitions

Electrical Units table

Name Symbol Quantity
Ampere (amp) A Electric current (I)
Volt V Voltage (V, E)
Electromotive force (E)
Potential difference (Δφ)
Ohm Ω Resistance (R)
Watt W Electric power (P)
Decibel-milliwatt dBm Electric power (P)
Decibel-Watt dBW 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 Ah Electric charge (Q)
Joule J Energy (E)
Kilowatt-hour kWh Energy (E)
Electron-volt eV 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-meter 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)
Decibel dB
Parts per million ppm

Units Prefix table

Prefix Symbol 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 103 1kΩ = 1000Ω
mega M 106 1MHz = 106Hz
giga G 109 1GHz = 109Hz

Electrical Units Definitions

Ampere (A)
Electrical unit of electrical current and measures the amount of electrical charge in an electrical circuit (per 1 second).

1A = 1C / 1s

Volt (V)
Electrical unit of voltage.

1V = 1J / 1C

Ohm (Ω)
Electrical unit of resistance.

1Ω = 1V / 1A

Watt (W)
Electrical unit of electric power and measures the rate of consumed energy.

1W = 1J / 1s
1W = 1V ⋅ 1A

Decibel-milliwatt (dBm)
Unit of electric power, measured with logarithmic scale referenced to 1mW.

10dBm = 10 ⋅ log10(10mW / 1mW)

Decibel-Watt (dBW)
Unit of electric power, measured with logarithmic scale referenced to 1W.

10dBW = 10 ⋅ log10(10W / 1W)

Farad (F)
Unit of capacitance. It represents the amount of electric charge in coulombs that is stored per 1 volt.

1F = 1C / 1V

Henry (H)
Unit of inductance.

1H = 1Wb / 1A

siemens (S)
Unit of conductance, which is the opposite of resistance.

1S = 1 / 1Ω

Coulomb (C)
Unit of electric charge.

1C = 6.238792×1018 electron charges

Ampere-hour (Ah)
Ampere-hour is a unit of electric charge.

One ampere-hour

1Ah = 1A ⋅ 1hour
1Ah = 3600C

Tesla (T)
Unit of magnetic field.

1T = 1Wb / 1m2

Weber (Wb)
Unit of magnetic flux.

1Wb = 1V ⋅ 1s

Joule (J)
Unit of energy.

1J = 1 kg ⋅ m2 / s2

Kilowatt-hour (kWh)
Unit of energy.

1kWh = 1kW ⋅ 1h = 1000W ⋅ 1h

Kilovolt-amps (kVA)
Unit of power.

1kVA = 1kV ⋅ 1A = 1000 ⋅ 1V ⋅ 1A

Hertz (Hz)
Unit of frequency. It measures the number of cycles per second.

1 Hz = 1 cycles / s