Enter any two of voltage, current, resistance or power and solve the rest instantly.
Enter any two of the four values — the other two are calculated automatically.
Formulas
Formulas
Voltage: V = I × R
Power: P = V × I
Power: P = I² × R
Power: P = V² ÷ R
Type any two of voltage (V), current (I), resistance (R) and power (P); the other two are solved instantly from Ohm's law. Use the unit dropdowns to enter or read values in V/mV, A/mA, Ω/kΩ or W/mW.