Skin Depth & Absorption Loss
Skin depth and absorption loss for a given thickness from frequency, conductivity and permeability. Copper at 1 MHz is about 66 µm.
Worked example
Input: Frequency 1 MHz, Conductivity σ 58 MS/m, Relative permeability μr 1, Thickness t 100 µm
Result: Skin depth δ 66.0855 µm, Absorption loss A 13.1436 dB
Result: Skin depth δ 66.0855 µm, Absorption loss A 13.1436 dB
Formula
δ = 1 / √(π·f·μ·σ)
A = 8.686 · t / δ (dB)
Copper: σ ≈ 58 MS/m, aluminium ≈ 35 MS/m
How it works
Skin depth δ is the depth at which the wave amplitude falls to 1/e: δ = 1/√(π·f·μ·σ). A conductor of thickness t gives an absorption loss of A = 8.686·t/δ dB. Use it to choose shield thickness and to estimate high-frequency resistance of ground conductors.
Practical tipThis calculator covers absorption loss only. Shielding effectiveness is reflection loss plus absorption loss, so even a thin metal film can shield electric fields and plane waves well thanks to reflection. Low-frequency magnetic shielding needs high-permeability material (high μr).
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Results and summaries are for reference. For certification and test reports use the latest official standard text and calibrated instrument data. Last updated: 2026-10-10