Wire Resistance Calculator
R = ρ(T) · L / A
How to Use This Calculator
Enter wire length, cross-sectional area, select material, and specify temperature. The tool computes DC resistance.
Formula
R = ρ(T) · L / A
ρ(T) = ρ20 · (1 + α · (T − 20°C))
- ρ20 (Cu) ≈ 1.724×10⁻⁸ Ω·m, α ≈ 0.00393/°C
- ρ20 (Al) ≈ 2.82×10⁻⁸ Ω·m, α ≈ 0.00403/°C
Frequently Asked Questions
Does AC change the result?
At high frequencies, skin effect increases effective resistance. This tool gives DC resistance.
Area in AWG?
Convert AWG to mm² first (use the Wire Gauge calculator), then compute resistance here.