Energy Density of Electromagnetic Fields Calculator

Compute the volumetric energy density of electric and magnetic fields with u = ½ε₀E² + B²/(2μ₀), returning the electric, magnetic, and total parts in J/m³.

Frequently Asked Questions

What is energy density of a field?

Energy per unit volume stored in an electric or magnetic field: u = ½ε₀E² + B²/(2μ₀), in J/m³.

Are the electric and magnetic contributions independent?

Yes - you add them. In an electromagnetic wave they're equal at any instant, so the total is twice either part.

Why does magnetism dominate at high B?

Because B² is divided by the very small μ₀, the magnetic contribution scales steeply. Strong magnets store enormous energy per cubic meter.

How do I convert gauss to tesla for energy density?

Divide the field in gauss by 10,000 to get tesla (1 T = 10,000 G), then apply u = B²/(2μ₀). For example, 5000 G = 0.5 T gives u ≈ 0.5² / (2 × 4π × 10⁻⁷) ≈ 9.9 × 10⁴ J/m³, while a 50 G refrigerator magnet (0.005 T) yields only about 10 J/m³. Always convert to tesla before using the formula.

Important Disclaimer: Estimates for informational purposes only.

This calculator provides estimates for informational purposes only. Results are based on assumptions and may not reflect actual outcomes. Consult qualified professionals in relevant fields before making important decisions based on these results.