Ohm’s Law Calculator

Ohm’s Law is the cornerstone of electrical circuit analysis. Understanding and applying it is crucial whether you’re an engineer, a student, or a hobbyist. But complex calculations can be a pain! That’s why we’ve created a free, easy-to-use online Ohm’s Law calculator. This tool will simplify your calculations and help you master Ohm’s Law quickly.

Ohm’s Law describes the relationship between voltage, current, and resistance in an electrical circuit. It’s a fundamental concept that allows you to design and analyze circuits and understand electricity flows.

Our free online calculator is here to make those calculations easy and precise.

Understanding Ohm’s Law

Let’s start by defining some key terms:

• Voltage (V): Voltage is the electrical pressure that drives current through a circuit. Think of it as the force pushing electrons. It is measured in Volts (V).
• Current (I): Current is the flow of electrical charge, or electrons, through a circuit. It is measured in Amperes (A or Amps).
• Resistance (R): Resistance is the opposition to the current flow in a circuit. It limits the current flowing through the circuit. It is measured in Ohms (Ω).

Now, here’s the formula for Ohm’s Law:

V = I * R

Where:

• V = Voltage (in volts)
• I = Current (in amps)
• R = Resistance (in ohms)

This simple formula allows you to calculate any one of these values if you know the other two. To make it even easier, you can use the Ohm’s Law Triangle:

Here’s how you can rearrange the formula to solve for different variables:

• To Calculate Voltage (V): If you know the current (I) and resistance (R), multiply the two: V = I * R
• To Calculate Current (I): If you know the voltage (V) and resistance (R), divide voltage by resistance: I = V / R
• To Calculate Resistance (R): If you know the voltage (V) and current (I), divide voltage by current: R = V / I

Ohm’s Law Equation

Ohm’s law states the relationship between electric current and potential difference. The current flowing through most conductors is directly proportional to the voltage applied to them. Georg Simon Ohm, a German physicist, proved Ohm’s law experimentally.

V = IR,

where V is the voltage across the conductor, I is the current flowing through the conductor and R is the resistance provided by the conductor to the flow of current.

Quadrant 1: Power (watts)

Power is the rate at which energy is used or produced.

• V x I (Voltage times Current)
• I² x R (Current squared times Resistance)
• V² / R (Voltage squared divided by Resistance)

Quadrant 2: Voltage (volts)

Voltage is the electrical “pressure” that pushes current through a circuit.

• P / I (Power divided by Current)
• √(P x R) (Square root of Power times Resistance)
• R x I (Resistance times Current)

Quadrant 3: Current (amps)

Current is the flow of electrical charge through a circuit.

• P / V (Power divided by Voltage)
• √(P / R) (Square root of Power divided by Resistance)
• V / R (Voltage divided by Resistance)

Quadrant 4: Resistance (ohms)

Resistance is the opposition to current flow in a circuit.

• V² / P (Voltage squared divided by Power)
• V / I (Voltage divided by Current)
• P / I² (Power divided by Current squared)

How to Use the Ohm’s Law Calculator

Step-by-Step Guide:

1. Select the Variable to Solve For
   • Choose whether you want to calculate Voltage (V), Current (I), or Resistance (R).
2. Enter the Known Values
   • Input the two known variables. For example:
     • Voltage and Resistance to find Current.
     • Current and Resistance to find Voltage.
3. Press “Calculate”
   • Click the “Calculate” button, and the calculator will instantly display the result.

Example Calculations:

1. Find Current (I):
   • Given: Voltage = 10V, Resistance = 5Ω
   • Formula: I = V ÷ R
   • Calculation: I = 10 ÷ 5 = 2A
2. Calculate Voltage (V):
   • Given: Current = 2A, Resistance = 3Ω
   • Formula: V = I × R
   • Calculation: V = 2 × 3 = 6V