Inductor Energy Calculator Formula

Understand the math behind the inductor energy calculator. Each variable explained with a worked example.

Formulas Used

Stored Energy

energy_mj = 0.5 * ind_h * pow(current_a, 2) * 1000

Stored Energy (J)

energy_j = 0.5 * ind_h * pow(current_a, 2)

Variables

VariableDescriptionDefault
inductance_mhInductance(mH)10
current_aCurrent(A)1
ind_hDerived value= inductance_mh / 1000calculated

How It Works

Inductor Energy Storage

E = 0.5 x L x I^2

Energy is stored in the magnetic field. It scales with the square of current.

Worked Example

10 mH inductor carrying 1 A.

inductance_mh = 10current_a = 1
  1. 01L = 10 mH = 0.01 H
  2. 02E = 0.5 x 0.01 x 1^2 = 0.005 J = 5 mJ

Frequently Asked Questions

Where is the energy stored?

In the magnetic field surrounding the inductor coil.

What happens when current is interrupted?

The inductor generates a voltage spike (back-EMF) trying to maintain current flow. This can damage circuits without protection.

Inductor vs capacitor energy?

Capacitor: E=0.5CV^2 (electric field). Inductor: E=0.5LI^2 (magnetic field).

Ready to run the numbers?

Open Inductor Energy Calculator