Ohm's Law Calculator

ohms-law

Ohm's Law

The above circuit can be used to explain Ohm's Law. Ohm's Law states that the voltage (V) across a resistor is proportional to the current (I), where the constant of proportionality is the resistance (R). i.e.

V = I * R

where

The Ohm's Law Calculator is the one of fundamental calculator used by any electrical engineer as it is one of the basic and important calculation used in any circuit. You can read more about Ohm's Laws under Electronics in Education. In the above calculator, enter any two values and click calculate to update other values. You can select unit from the drop-down list against to the input field of the parameter and enter the value in the text input field. Enter only know values, leave other values blank which you want to find and hit calculate, it'll update the other values.

The calculator accepts scientific notations such as "e" or "E" (meaning exponent). Since, it is not possible to show the results as accurate as natural, we are rounding off the results to 10 decimal places. This means that the results will be rounded to avoid numbers getting too long.

Ohm's Law is being widely used in analyzing any circuit which constitutes a conductor with certain resistance and electricity flowing through it. Ohm's is used by a learner to find current limiting resistor in his first circuit or by an engineer working on an rocket design.

We are using below formulas in our calculator. To the best of our knowledge, we hope that the calculations we are performing are accurate. If you find any errors, please write to us at contactus@efaelectronicsforall.com . We will rectify.

The below pie chart shows relation ship between Voltage (V), Current (I), Resistance (R) and Power (P).

ohms-law

Ohm's Law Pie Chart

You can derive below formulas from Ohm's Law

V = I * R


V =
P
–––
I


V = √(P * R)


I =
V
–––
R


I =
P
–––
V


I =
√(
P
–––
R

 
)


R =
V
–––
I


R =
V2
–––
P


R =
P
–––
I2


P = V * I


P = R * I2


P =
V2
–––
R


In the below example, we will calculate Power (P) and Current (I) for Input Voltage (V) - 12V and Resistance (R) - 1KΩ. Let us calculate Current (I) first.
From the above formula list we have,

I =
V
–––
R
=
12V
–––
1KΩ
=
12V
–––
1000
= 0.012 = 12mA


Now we know Current (I) and Voltage (V), let us calculate Power (P) using them.

P = V * I = 12V * 12mA = 12 * 0.012 = 0.144W = 144mW


V = 12V, I = 12mA, R = 1KΩ, and P = 144mW