Ohm's Law Power Formulas and Pie Chart

Whether you are a seasoned veteran or a newbie to electronics an Ohms law chart is something that is always good to have around.

Ohms law power formulas and pie chart

The Ohm Law formulas above show the relationship between Voltage, Amps, Watts, and Ohms.  If you know two of them, you can calculate the other two.

  • P=Watts - The rate of energy conversion
  • R=Ohms - The electrical resistance
  • I=Amps - The amount of electricity passing through a point
  • E=Volts - The potential electrical difference between two points


  • V=I*R
  • V=√(P*R)
  • V=P/I


  • P/I²
  • E/I
  • E²/P


  • E/R
  • √(P/R)
  • P/E


  • I*I²/R
  • E*I
  • E²/R
I also found this humorous but very good visual explanation of Ohms law at

Next Steps

Go to the Analog Circuits Training Lesson Series to select your next lesson.  There are also many other Lesson Series on PLC Programming and Industrial Automation.