⚡ Electrical Engineering
Power Calculator
Calculate electrical power, current, voltage, and resistance using Ohm's Law.
Voltage (V)
V
Voltage in volts (V)
Current (I)
A
Current in amperes (A)
Resistance (R)
Ω
Resistance in ohms (Ω)
Power Factor (PF)
Power factor (0-1), for AC circuits
Power 0%
Power (P)
0 W
real power
Apparent Power 0 VA
Reactive Power 0 VAR
Power Factor 0.85
Voltage × Current 0 VA

📐 Ohm's Law Formulas

P = V × I
Power = Voltage × Current
V = I × R
Voltage = Current × Resistance
I = V ÷ R
Current = Voltage ÷ Resistance
P = I² × R
Power = Current² × Resistance

📊 Calculation Breakdown

Parameter Value Formula

How the formula works

P = V × I × PF  |  S = V × I  |  Q = √(S² − P²)  |  V = I × R
  • P (Real Power) = V × I × PF — Actual power consumed (Watts)
  • S (Apparent Power) = V × I — Total power in circuit (VA)
  • Q (Reactive Power) = √(S² − P²) — Power stored and returned (VAR)
  • PF (Power Factor) = P ÷ S — Efficiency of power usage (0-1)
  • V = I × R — Ohm's Law: Voltage = Current × Resistance