Created By : Vaibhavi Kumari

Reviewed By : Rajashekhar Valipishetty

Last Updated : May 10, 2023

The Ohm’s Law Calculator is a useful tool for determining the voltage, current, and power relationship. Simply type in the two parameters, and the unknown parameter will appear in a flash.

Choose a Calculation
Voltage (V):
Current (I):

What is Meant by Ohm’s Law?

According to Ohm's law, the potential difference between two points in a circuit is directly proportional to the current running through the circuit and the resistance of the circuit.

Ohms Law Formula

The formula that defines Ohm's law is; V = IR

  • Where, V = difference in voltage or potential.
  • I = current
  • R = conductor's resistance

The electrical circuit's current, voltage, and resistance are calculated using Ohm's law. The voltage drop across electrical components is controlled using this law.

Applications of Ohm's Law

  • Ohm's law is most commonly used to determine an electric circuit's voltage, resistance, or current.
  • To keep the desired voltage drop across the electronic components, Ohm's law is applied.
  • Ohm's law is also utilised to divert current in DC ammeters and other DC shunts.

Limitations of Ohm's Law

The following are some of Ohm's law's limitations

  • Ohm's law does not apply to unilateral electrical elements like diodes and transistors since they only allow current to flow in one direction.
  • Voltage and current will not be constant concerning time with non-linear electrical elements with factors like capacitance, resistance, and so on, making Ohm's law difficult to apply.

For more concepts check out to get quick answers by using this free tool.

Voltage Formula

Finding Voltage is one of Ohm’s Law's most basic concepts. To get the Voltage, we can rewrite the calculation above as V= IR. If you know the current and resistance, you can easily compute the voltage by replacing them in the formula above. Volts are the units of voltage.

How to Calculate Power?

Power is another value that can be determined using Ohm's Law as a foundation. The formula P = V x I expresses power as the product of voltage and current. Watts are the units of power.

Ohm's Law for Anisotropic Material

Ohm’s Law can also be expressed in terms of the location of electrical properties within a conductor. If the particular resistance of conductive materials is independent of the applied field value and direction. The formula for calculating Ohm's law is

ρ = E / J

  • Where, ρ = specific resistance of the conductive material
  • E = Electric Field of the Vector
  • J = Current Density Vector

When working with anisotropic materials like wood or graphite, the above formula can be quite useful.

How to Use the Ohms Law Calculator?

The following is the procedure how to use the Ohms law calculator

  • Fill in the appropriate input fields with voltage, resistance, or current.
  • To acquire the result, click the "Calculate" button.
  • Finally, in the new window, the resistance, voltage, and current will be presented.

Examples on Ohm’s Law Calculations

Question 1: A current of 4.2 A passes through an electric iron with a resistance of 60. Calculate the difference between two places in terms of voltage?


Given: I = 4.2A

R = 60

V = IR = 4.2 x 60 = 252v

Question 2: A fully resistive electrical equipment is connected to an EMF source of 7.0 V. (a light bulb). It is powered by a 3.0 A electric current. Assume that the conducting wires have no resistance. Determine how much resistance the electrical appliance provides?


Given: V = 7.0v

I = 3.0A

V = IR

R = V/I = 7.0/3.0 = 2.33Ω

FAQs on Ohm’s Law Calculator

1. How many amperes does one ohm contain?

One. We'll assume you're working with amperes and volts/ohms. The ampere is the SI base unit for electric current.

2. What is the application of Ohm's Law?

Ohm's law is used to validate the static values of circuit components such as current levels, voltage supplies, and voltage drops.

3. How many ohms in 100 watts?

8 ohms. It's worth noting that the power output (100 watts) is at a set load (8 ohms). This means that the maximum output power of an 8-ohm speaker will be 100 watts.

4. Is there a difference between ohms and K ohms?

One kilo ohm is equal to 1,000 ohms, which is the resistance between two points of a conductor carrying one amp at one volt.