Model conductor behavior across changing electrical conditions today. Review AC resistance, depth, and loss trends. Improve cable sizing decisions with practical frequency-based performance insights.
Use the preset material list or enter custom properties for more advanced analysis.
This tool uses a practical engineering model for a solid round conductor.
ρ(T) = ρref × [1 + α × (Top − Tref)]
Operating resistivity is corrected using the material temperature coefficient.
δ = √( ρ(T) / (π × f × μ) )
Skin depth depends on operating resistivity, frequency, and magnetic permeability.
A = πr²
This is the full cross-sectional area of the round conductor.
Aeff = π × [r² − max(r − δ, 0)²]
This approximates the annular region carrying most alternating current.
Rdc = ρ(T) × L / A
Rac = ρ(T) × L / Aeff
AC resistance rises as the effective conducting area becomes smaller.
Skin Factor = Rac / Rdc
This ratio shows how much extra resistance appears under alternating current.
This approximation is excellent for fast design comparisons. Very high-frequency work, non-round conductors, and strong proximity effects may require Bessel-function methods or field simulation.
Sample case: copper conductor, 10 m length, 10 mm diameter, 20°C, one conductor, 25 A RMS.
| Frequency (Hz) | Skin Depth (mm) | DC Resistance (Ω) | AC Resistance (Ω) | Skin Factor | AC Loss at 25 A (W) |
|---|---|---|---|---|---|
| 50 | 9.345526 | 0.00219506 | 0.00219506 | 1.000000 | 1.37191561 |
| 60 | 8.531259 | 0.00219506 | 0.00219506 | 1.000000 | 1.37191561 |
| 400 | 3.304142 | 0.00219506 | 0.00248040 | 1.129991 | 1.55025248 |
| 1,000 | 2.089723 | 0.00219506 | 0.00331976 | 1.512375 | 2.07485123 |
| 10,000 | 0.660828 | 0.00219506 | 0.00889181 | 4.050820 | 5.55738255 |
Skin effect becomes more noticeable when frequency rises, permeability increases, or conductor diameter becomes large compared with skin depth.
Fine strands, hollow conductors, and geometry changes can reduce unnecessary copper use and help control loss at higher frequencies.
This calculator isolates skin effect. Closely packed conductors may also suffer proximity effect, which can raise total AC resistance further.
Skin effect is the tendency of alternating current to crowd near a conductor’s surface. As frequency rises, less cross-sectional area carries current, so effective resistance increases.
No. It uses an engineering annulus approximation for solid round conductors. It is excellent for quick design screening, but extreme frequencies, complex shapes, and proximity effect may require field solvers.
DC resistance stays nearly uniform because current fills the full cross-section. AC resistance can rise because current concentrates near the surface as frequency increases.
Relative permeability strongly affects skin depth. Ferromagnetic materials can produce much smaller skin depth and much higher AC resistance than nonmagnetic conductors at the same frequency.
Skin depth is the approximate depth where current density falls to about 37% of its surface value. Smaller skin depth means current is confined closer to the conductor surface.
It can estimate loss if you enter RMS current. The calculator reports AC power loss using I²R, which helps compare heating impact across materials and frequencies.
Yes. Parallel identical conductors reduce the total resistance by sharing current. This tool divides the single-conductor resistance by the number of parallel paths entered.
Use it for preliminary engineering estimates, cable comparisons, and educational analysis. For tightly packed windings, busbars, plated conductors, or RF layouts, also check proximity and geometry effects.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.