Energia em Indutor
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
E = ½LI²
About this calculator
The Inductor Energy Calculator determines the energy stored in the magnetic field of an inductor using the formula E = ½ L I², where E is energy in joules, L is inductance in henries, and I is current in amperes. It is useful for designing circuits with inductors, such as switching power supplies, filters, and energy storage systems.
To use, enter the inductance and current. The calculation is instantaneous and considers the energy accumulated when the current is constant. Note that energy is proportional to the square of the current, so small current variations cause large energy differences.
Use this tool when designing circuits that store energy in magnetic fields, such as DC-DC converters, ignition coils, or inductive charging systems. It helps size components and predict energy behavior.
Cautions: the formula assumes an ideal inductor with no resistance or saturation. In real inductors, ohmic losses and nonlinearities can reduce available energy. Also ensure the current is within the component's limits.
Frequently asked questions
What does the energy stored in an inductor mean?
It is the energy accumulated in the magnetic field when an electric current flows through the inductor. This energy can be released when the current decreases.
Can I use the calculator for any type of inductor?
Yes, as long as the inductance is known. But remember that real inductors have losses, so the calculated energy is ideal.
Does the energy depend on the current frequency?
Not directly. The formula assumes constant current (DC). For alternating current (AC), the instantaneous energy varies, but using RMS current gives an approximation.
How does the inductor's resistance affect the energy?
Resistance dissipates energy as heat, reducing the energy available in the magnetic field. In real inductors, some energy is lost.
What is the unit of energy used?
Energy is calculated in joules (J). For small values, it can be expressed in millijoules (mJ) or microjoules (µJ).