Ohm’s Law Calculator

Find the relationship between voltage, current, and resistance in an electrical circuit. Enter any two values to calculate the third automatically.

⚡ Circuit Parameters

Calculated Solution

Awaiting Inputs…
Enter any two values on the left to see the step-by-step derivation.

Quick Reference

  • Voltage (V) $V = I \times R$
  • Current (I) $I = V / R$
  • Resistance (R) $R = V / I$
  • Power (P) 0 Watts

What is Ohm’s Law?

Ohm’s Law is the most fundamental principle in electrical engineering. Discovered by Georg Simon Ohm in 1827, it states that the current passing through a conductor between two points is directly proportional to the voltage across the two points.

The Magic Triangle Method

To remember the formulas easily, imagine a triangle with V at the top and I and R at the bottom. To find a variable, cover it with your hand and the remaining variables show the operation:

  • Find V: $I \times R$
  • Find I: $V / R$
  • Find R: $V / I$

Real-World Application

Imagine a water pipe. The Voltage is the water pressure, the Current is the flow rate of the water, and the Resistance is the size of the pipe. If you increase the pressure (Voltage) or make the pipe wider (decrease Resistance), more water (Current) flows through.

Did you know?

All tools on Physics Fundamentals use high-precision floating-point math to ensure your laboratory circuits and school projects are perfectly calculated.