Ohm's law calculator

V = I × R P = V × I

Enter any two values; the other two solve automatically.

How to use Ohm's law calculator

  1. Enter any two of voltage, current, or resistance.
  2. The third value calculates automatically using V = I × R, along with power via P = V × I.

About this tool

Ohm's law calculator is a single-purpose utility on instant.tw, a free toolbox of calculators, converters, generators, and quick lookups. Everything works in your browser — nothing is uploaded, nothing is stored on a server unless explicitly noted.

Category: Electrical & Electronics. Browse more Electrical & Electronics tools.