Calculate electrical power, voltage, current, or resistance.
Inputs (Enter any 2)
Calculated Values
Enter at least 2 values
About this calculator
Quick Reference
PPower (Watts)
VVoltage (Volts)
ICurrent (Amps)
RResistance (Ohms)
Overview
This tool solves for Power (P), Voltage (V), Current (I), or Resistance (R) using Ohm's Law and the Power Law. Enter any two known values to find the others.
💡
Pro Tips
P = V × I (Power Law)
V = I × R (Ohm's Law)
For AC circuits, this calculates real power for resistive loads or apparent power (VA) roughly.
!
Fun Facts
"James Watt, whom the unit is named after, improved the steam engine."
"One horsepower is approximately 746 Watts."
"A typical LED bulb uses about 9-10 Watts to produce the same light as a 60 Watt incandescent bulb."
