Skin Effect Calculator Formula
Understand the math behind the skin effect calculator. Each variable explained with a worked example.
Formulas Used
Skin Depth
skin_depth_mm = sqrt(rho_ohm_m / (pi * freq_hz * rel_permeability * 4 * pi * 1e-7)) * 1000Variables
| Variable | Description | Default |
|---|---|---|
frequency_mhz | Frequency(MHz) | 1 |
resistivity_uohm_cm | Resistivity(uΩ-cm) | 1.72 |
rel_permeability | Relative Permeability | 1 |
freq_hz | Derived value= frequency_mhz * 1000000 | calculated |
rho_ohm_m | Derived value= resistivity_uohm_cm * 1e-8 | calculated |
How It Works
Skin Effect
delta = sqrt(rho / (pi x f x mu))
At high frequencies, current concentrates near the conductor surface. The skin depth is the depth at which current density falls to 1/e (37%) of the surface value.
Copper at 1 MHz: skin depth is about 0.066 mm.
Worked Example
Copper at 1 MHz.
frequency_mhz = 1resistivity_uohm_cm = 1.72rel_permeability = 1
- 01rho = 1.72e-8 ohm-m
- 02mu = 4pi x 1e-7 H/m
- 03delta = sqrt(1.72e-8 / (pi x 1e6 x 4pi x 1e-7))
- 04delta = 0.066 mm
Ready to run the numbers?
Open Skin Effect Calculator