This Ohms Law calculator calculates any two from voltage, current, resistance or power based on the other two given variables from the Ohms law formula. You can more on this topic below the tool.

Enter only two from the four variables:
Voltage [V]:
Resistance [R]:
Current [I]:
Power [P]:

How does this Ohms Law calculator work?

In case you know 2 out of the 4 variables from Ohms law you can determine the other two figures by applying these formulas:

[V] = [C] * [R]

[R] =  [V] / [C]

[C] = [V] / [R]

[P] = [V] * [C] = ([V]^2) / [R] = ([C]^2) * [R]


[V] = Voltage

[C] = Current

[R] = Resistance

[P] = Power

In regard of the units that can be processed by this Ohms Law calculator, depending on the variable in question here are the energy measurement units that are supported:

  • Voltage can be either in Kilovolt, Volt or Milivolt.
  • Resistance can be expressed either in Ohm, KiloOhm or MegaOhm.
  • Current can be entered either in Ampere, Miliapere or Kiloampere.
  • Power can be input either in Watt, Kilowatt, Megawatt or Horsepower.

13 Apr, 2015