Surface Current Density Converter

Surface current density measures electric current flowing per unit area of a conductor surface. Essential for skin effect analysis, antenna engineering, and PCB trace capacity calculations.

Common Surface Current Density Conversions

FromTo
1 A/m²0.0001 A/cm²
1 A/cm²10,000 A/m²
1 kA/m²0.1 A/cm²
1 mA/m²0.001 A/m²
10 A/cm²100,000 A/m²
1 MA/m²100 A/cm²

Surface Current Density Unit Definitions

A/m² (amperes/m²)
SI unit of current density.
A/cm²
10,000 A/m². Common in power electronics.
kA/m²
1,000 A/m². High-current applications.
mA/m²
0.001 A/m². Leakage currents and surface oxidation.

Frequently Asked Questions

What is the skin effect?

At high frequencies, current concentrates near the conductor surface. At 50 Hz in copper, skin depth ≈ 9 mm; at 1 MHz, ≈ 66 µm. Surface current density increases with frequency.

What is a safe current density for copper conductors?

Typical guideline: 3–6 A/mm² (3–6 MA/m²) for power wiring. PCB traces follow IPC-2221 tables based on width and temperature rise.

What is the difference between surface and volume current density?

Volume current density J (A/m²) applies to bulk conductors. Surface current density applies when current is confined to a thin surface layer, as in the skin effect.