Skin Depth
Calculate the skin depth of a conductor at a given frequency — how deep high-frequency current penetrates — free online.
About this calculator
Skin depth δ = √(2ρ ÷ (ωμ)) = √(ρ ÷ (π f μ₀ μr)). At 60 Hz copper has δ ≈ 8.5 mm; at 1 MHz about 66 µm. AC resistance rises as current crowds near the surface, so RF conductors use thin wires or plating.