• Calculation: electrical voltage, current, resistance, and power •

The nominal impedance Z = 4, 8, and 16 ohms (loudspeakers) is often assumed as resistance R.
Ohm's law: E = R × I and power law: P = E × I.
P = power, I = intensity, E = electro motive force (EMF = voltage), V = voltage, potential difference, R = resistance.

Enter any TWO of the following values, then press the calculate button.
The missing values will be calculated. Enter two values.
voltage E or V  volts V
current I  amperes, amps A
resistance R  ohms Ω
power P  watts W
Formula wheel   All formulas:
power, voltage, current, resistance

V or E from "voltage" or "electro motive force"