Ohm’s Law Online Calculator

What is Ohm’s Law?

Ohm’s law dictates that the voltage across a conductor is directly related to the current passing through it, as long as all physical conditions and temperatures stay the same. Ohm’s Law states that the current flowing through a conductor is directly proportional to the voltage across the circuit, i.e. V is directly proportional to I.

In other words, as the voltage applied increases, the current through the conductor also increases proportionally. Since Ohm’s Law establishes the fundamental relationship between voltage and current in an electric circuit, it is regarded as a fundamental principle that aids in the analysis and understanding of electric circuits.



  • V is the voltage (potential difference) across the conductor, measured in volts (V).
  • I is the current flowing through the conductor, measured in amperes (A).
  • R is the resistance of the conductor, measured in ohms (Ω).

So we can find three parameters as,

Voltage: V=I×R

Current: I=V/R

Resistance: R=V/I

Online Calculator:

Ohm's Law Calculator


Sample Calculation:

Suppose you have a circuit with a resistance of 10 Ω and you want to find the current flowing through it when a voltage of 20 V is applied. Using Ohm’s Law:


=20 V /10 Ω=2 A

This means the current flowing through the circuit is 2 amperes.

Graphical Representation:

Source – Internet

When voltage (V) is plotted on the y-axis and current (I) on the x-axis, the slope of the resulting line represents the resistance (R). The line is straight, indicating a linear relationship between voltage and current for a constant resistance.

Ohm’s Law is used to design and analyze electrical and electronic circuits. For example, in a simple circuit with a battery and a resistor, Ohm’s Law helps to determine the current flowing through the circuit or the voltage drop across the resistor.

Read More : Ohms Law


  • Aids in ascertaining the voltage, current, and resistance in electrical circuits.
  • Crucial for examining both simple and intricate circuits to ensure proper functionality.
  • Aids engineers in creating components like resistors, capacitors, and inductors to achieve desired electrical properties.
  • Facilitates the computation of power consumption in electrical devices using a specific formula.
  • Utilized for diagnosing and resolving issues in circuits by measuring and comparing expected versus actual values of voltage, current, and resistance.
  • Ensures that circuits operate within safe voltage and current limits, preventing overheating and potential hazards.
  • Assists in selecting suitable batteries and power supplies based on the required voltage and current for devices.
  • Used in calibrating and testing electrical instruments to ensure accurate measurements.
  • Critical for creating voltage dividers, which are circuits that produce a specific output voltage from a higher input voltage.
  • Determines the correct resistance needed to control the current through LEDs or motors, protecting them from damage.
  • Utilized to design and analyze heating elements in appliances by relating resistance to heat generation.
  • A fundamental concept taught in electrical engineering and physics to establish a foundation for more complex theories and applications.

Read More : Ohms Law


Subramanian MK, currently serving as a workshop instructor at Sakthi Polytechnic College, Erode Tamil Nadu. With a career spanning 25 + years, Subramanian MK has dedicated himself to advancing knowledge in Electronics and Communication Engineering (ECE). His passion for exploring new technologies has led to the development of numerous projects, showcasing expertise in IoT and PCB design.

Articles: 504

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.


Hi, How can I help you?