Inductor Energy Calculator

About this calculator

This calculator finds the magnetic energy stored in an inductor using E = ½ · L · I², where L is inductance in henries and I is the current flowing through the coil in amperes. That energy is stored in the magnetic field generated by the current, analogous to how a capacitor stores energy in an electric field via E = ½CV².

This relationship governs how much energy a choke, transformer winding, or solenoid can hold and release, which is critical when sizing inductors for switch-mode power supplies, flyback converters, and buck/boost regulators — engineers need to know the peak energy an inductor must handle without saturating its core.

Electrical and electronics engineers designing power supply circuits, hobbyists building DC-DC converters, and students in electromagnetism courses working through inductor problems use this formula. Enter the inductance and current to get the stored energy in joules.