Ohm's Law & Watt's Law Calculator
Electrical Properties

Electromotive Potential
Measured in Volts, is represented by the letter V (or E)

Current
Measured in Amperes, is represented with the letter I

Resistance
Measured in Ohms, is represented by the letter R (or the Greek letter Ω)

Power
Measured in watts, is represented by the letter W
Ohm's Law
States the relationship between voltage, current and resistance. Given the relationship between these three elements, once you know any two of them, it is possible to calculate the third.

V = IR
Volts = Amps x Ohms

I = ^{V}/_{R}
Amps = Volts / Ohms

R = ^{V}/_{I}
Ohms = Volts / Amps
Watt's Law
Watt's Law is similarly useful in figuring out the relationship between power, voltage and current.

W = VI
Watts = Volts x Amps

V = ^{W}/_{I}
Volts = Watts / Amps

A = ^{W}/_{V}
Amps = Watts / Volts