Ohm's Law Calculator

Voltage

Current

Resistance

Power

Please Enter Any Two Values

Understanding Ohm’s Law:

Ohm's Law is a fundamental principle in electronics and physics that relates voltage, current, and resistance in an electric circuit. It's a crucial concept for anyone working with electronics, and this article explains Ohm's Law in detail, with examples, formulas, and an easy-to-use calculator to help you perform accurate calculations effortlessly.

What is Ohm’s Law?

Ohm’s Law states that the current (I) flowing through a conductor between two points is directly proportional to the voltage (V) across the two points, and inversely proportional to the resistance (R) of the conductor. This relationship is mathematically represented as:

V = I × R

Where:

V is the voltage in volts (V),
I is the current in amperes (A),
R is the resistance in ohms (Ω).

Ohm’s Law Formula Breakdown

Ohm's Law can be expressed in three key forms depending on which variable you want to calculate:

1. Voltage (V) Calculation:

V = I × R

To calculate voltage, multiply the current by the resistance. This form is useful when you know the current and resistance but need to determine the voltage.

2. Current (I) Calculation:

I = V / R

To calculate current, divide the voltage by the resistance. This form is helpful when you know the voltage and resistance but want to find the current.

3. Resistance (R) Calculation:

R = V / I

To calculate resistance, divide the voltage by the current. Use this form when you have voltage and current values but need to find the resistance.

Power in Electrical Circuits

Along with Ohm’s Law, the power consumed in a circuit is another important calculation. The power (P) is calculated by the formula:

P = V × I

Where:

P is the power in watts (W),
V is the voltage in volts (V),
I is the current in amperes (A).

Other forms of the power formula derived from Ohm’s Law are:

P = I² × R (When you know the current and resistance)
P = V² / R (When you know the voltage and resistance)

How to Use the Ohm's Law Calculator

The Ohm's Law calculator allows you to input any two values from voltage, current, resistance, or power, and automatically calculates the missing R V I P parameters.

Example 1: Finding Resistance

Let’s say you have a circuit with a voltage of 10V and a current of 2A. To find the resistance, use the formula:

R = V / I = 10V / 2A = 5Ω

The calculator will give you the same result by simply entering 10V in the voltage field and 2A in the current field.

Example 2: Finding Current

Suppose you know the voltage is 5V and the resistance is 2Ω, but you need to find the current. The formula is:

I = V / R = 5V / 2Ω = 2.5A

In the calculator, you’d enter 5V in the voltage field and 2Ω in the resistance field, and it will calculate the current as 2.5A.

Example 3: Finding Power

Imagine a scenario where you have a circuit with 10V and 2A, and you want to calculate the power consumed. The formula is:

P = V × I = 10V × 2A = 20W

Inputting the values 10V for voltage and 2A for current into the calculator will display 20W for power.

Example 4: Finding Voltage

If you have a small current of 200mA and a resistance of 5Ω, and you need to find the voltage, you’d use the formula:

V = I × R = 200mA × 5Ω = 0.2A × 5Ω = 1V

In the calculator, input 200mA for current and 5Ω for resistance. It will calculate the voltage as 1V.

Features of the Ohm’s Law Calculator

Auto-Calculation: The calculator automatically computes the missing values once two input fields are filled. No need to press a “Calculate” button.
Unit Selection: Users can choose units such as volts (V), millivolts (mV), amperes (A), milliamps (mA), ohms (Ω), milliohms (mΩ), kilovolts (kV), kilowatts (kW), and many others. The calculator adjusts calculations accordingly.
Freezing Inputs: Once two input fields are provided, the remaining fields are automatically frozen to prevent further input. This ensures no conflicting data is entered and maintains calculation integrity.
Real-Time Output: As soon as the inputs are provided, the calculated output is displayed in real-time.

Conclusion

Understanding Ohm's Law is essential for working with electrical circuits. With this easy-to-use calculator, you can quickly determine voltage, current, resistance, and power with just two known values. Whether you're using standard units or milli-units, the calculator efficiently handles all the conversions and calculations for you, saving time and minimizing the chance of error.

Try the Ohm's Law Calculator above to explore how easy and practical it is to apply Ohm's Law in real-world scenarios. Whether you're a student, engineer, or electronics enthusiast, this tool will be a valuable resource in your work.