Power Calculator (P = VI)

Calculate electrical power, voltage, current, and resistance. Enter any two known values to compute the rest.

Calculation Tool

Enter EXACTLY two values to calculate the other two

Ohm's Law Power Wheel

For Power (P)

  • P = V × I
  • P = I² × R
  • P = V² / R

For Voltage (V)

  • V = I × R
  • V = P / I
  • V = √(P × R)

For Current (I)

  • I = V / R
  • I = P / V
  • I = √(P / R)

For Resistance (R)

  • R = V / I
  • R = V² / P
  • R = P / I²