Below are some of the more common definitions and math to go along with them.
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 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 is the electrical unit of resistance.
1Ω = 1V / 1A
Watt is the electrical unit of electric power. It measures the rate of consumed energy.
1W = 1J / 1s
1W = 1V · 1A
Decibel-milliwatt or dBm is a unit of electric power, measured with logarithmic scale referenced to 1mW.
10dBm = 10 · log10(10mW / 1mW)
Decibel-watt or dBW is a unit of electric power, measured with logarithmic scale referenced to 1W.
10dBW = 10 · log10(10W / 1W)
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 is the unit of inductance.
1H = 1Wb / 1A
siemens is the unit of conductance, which is the opposite of resistance.
1S = 1 / 1Ω
Coulomb is the unit of electric charge.
1C = 6.238792×1018 electron charges
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 is the unit of magnetic field.
1T = 1Wb / 1m2
Weber is the unit of magnetic flux.
1Wb = 1V · 1s
Joule is the unit of energy.
1J = 1 kg · 1(m / s)2
Kilowatt-hour is a unit of energy.
1kWh = 1kW · 1h = 1000W · 1h
Hertz is the unit of frequency. It measures the number of cycles per second.
1 Hz = 1 cycles / s
Special thanks goes out to the guys at RapidTables.com for putting this together