Enter the inductance (Henries, h) and the current (amps) into the calculator to determine the Magnetic Energy. 

Magnetic Energy Formula

The following equation is used to calculate the Magnetic Energy. 

Em = .5 * L * I ^2


  • Where Em is the Magnetic Energy (Joules)
  • L is the inductance (Henries, h) 
  • I is the current (amps) 

To calculate the magnetic energy, multiply the inductance by the current squared, then divide by 2.

How to Calculate Magnetic Energy?

The following two example problems outline the steps and information needed in order to calculate the Magnetic Energy.

Example Problem #1:

  1. First, determine the inductance (Henries, h). In this example, the inductance (Henries, h) is measured to be 10.
  2. Next, determine the current (amps). For this problem, the current (amps) is calculated to be 2.
  3. Finally, calculate the Magnetic Energy using the formula above: 

Em = .5 * L * I ^2

Inserting the values from above and solving the equation with the imputed values gives: 

Em = .5 * 10 * 2 ^2 = 20 (Joules)

Example Problem #2: 

Using the same process as example problem 1, we first define the needed variables outlined by the formula. In this case, the values are provide as: 

inductance (Henries, h) = 20

current (amps) = 3

Entering these values into the formula or calculator above gives us:: 

Em = .5 *20*3 ^2 = 90 (Joules)