PCB Trace Resistance Calculator
Calculate the DC resistance of a copper PCB trace from its length, width, and copper thickness.
What this calculator does
Copper PCB traces have measurable DC resistance that depends on their dimensions. This calculator estimates that resistance from trace length, width, and copper weight (thickness), with a small correction for copper’s temperature coefficient.
The formula
It uses the standard resistivity formula R = ρ × L / A, where L is trace length, A is the trace’s cross-sectional area (width × thickness), and ρ is copper’s resistivity, adjusted for temperature using ρ = ρ₀ × (1 + α(T − 20°C)) with ρ₀ = 1.68×10⁻⁸ Ω·m at 20°C and a temperature coefficient α of about 0.00393 per °C.
This is a straightforward DC resistance estimate for planning trace losses and voltage drop; it does not account for AC skin effect at very high frequencies.