Energy Density of Fields Calculator

Find the energy density stored in electric and magnetic fields.

Total energy density (J/m³) 99,471.84
Electric part (J/m³) 0
Magnetic part (J/m³) 99,471.84

Formula: u = ½·ε₀·E² + B² ÷ (2·μ₀)

Step-by-step with your numbers:
1. Values used:
2. Electric field = 1,000 V/m
3. Magnetic field = 0.5 T
4.
5. Total energy density = 99,471.84J/m³
6. Electric part = 0J/m³
7. Magnetic part = 99,471.84J/m³
Did we solve your problem today?

Electric and magnetic fields store energy per unit volume.

The math behind it

u = ½·ε₀·E² (electric) + B²/(2μ₀) (magnetic). Magnetic energy density is usually far larger for everyday fields.

Worked example

1000 V/m and 0.5 T → about 99,500 J/m³ (almost all magnetic).

FAQ

Where is field energy stored?

In the field itself, throughout the region it occupies.