Ohm's Law Calculator

Ohm's Law Solver

Calculate Voltage, Current, or Resistance.

Active Formula

Formula Triangle

VIR

Circuit Representation

VRI →
Solving for Voltage

Understanding Ohm's Law

Ohm's Law states that the current through a conductor between two points is directly proportional to the voltage across the two points.

  • Voltage (V): The electrical potential difference, measured in Volts.
  • Current (I): The rate of flow of electric charge, measured in Amperes.
  • Resistance (R): A material's opposition to the flow of electric current, measured in Ohms ($\Omega$).

Ohm's Law Guide Guide

How to Use

  1. 1Choose which variable to calculate: Voltage (V), Current (I), or Resistance (R).
  2. 2Enter the two known values.
  3. 3Click calculate to solve for the third value.
  4. 4The calculator will also compute the Power (P) in Watts.

Formula & Logic

Ohm's Law states that the current flowing through a conductor is directly proportional to the voltage applied across it and inversely proportional to the resistance.

V= Voltage (Volts)
I= Current (Amperes)
R= Resistance (Ohms)
P= Power (Watts) = V × I

Practical Applications

Electronics Design

Determine the correct resistor value needed to protect an LED from burning out.

Troubleshooting

Diagnose electrical circuits by checking if the measured current matches the expected value.

Power Consumption

Calculate how much power a device consumes to estimate battery life or energy costs.

Frequently Asked Questions

Q.What is Ohm's Law?

Ohm's Law is a fundamental formula used in electronics to calculate the relationship between voltage, current, and resistance. It is named after German physicist Georg Ohm.

Q.What happens if resistance increases?

According to Ohm's Law (I = V/R), if voltage remains constant, increasing resistance will decrease the current flow.

Q.Can I use this for AC circuits?

Ohm's Law applies to AC circuits containing only resistive elements. For circuits with capacitors or inductors, you must use Impedance (Z) instead of Resistance (R).