Ohm's law calculator

Fill any two of voltage, current, resistance, and power — get the other two.

Fill any two fields; leave the rest blank.

Calculated in this browser. Nothing is sent anywhere.

Ideal DC math only — real circuits add tolerances, temperature drift, and impedance on AC that this does not model.

How to use

  1. Enter any two values.
  2. Leave the unknowns blank.
  3. Read all four quantities.

What it supports

Ideal DC relationships only — AC impedance, tolerance, and temperature effects are not modeled.

Related tools

Related guides