Ohm's Law Calculator

Ohm's law ties voltage, current and resistance together, and the power relation brings watts into the same set. Fill in any two of volts, amps, ohms and watts and this returns the other two, along with the formulas it used and unit prefixes from microamps to kilovolts. All six pairs are covered, including resistance and power, which is solved with a square root. It is the direct current form, which also holds for a purely resistive alternating current circuit, so a motor or any other reactive load needs impedance and a power factor instead.