# Trace Resistance Calculator

This calculator calculate the resistance of a copper trace based on width, length, thickness and temperature. The resistance of a trace is important to estimate the power dissipate in a trace or to estimate roughly the voltage drop from a voltage supply based on the current flowing through the trace. The resistance in real life will vary a bit since conductor are not exactly rectangular. The trace on a printed circuit boards is more of a trapezoidal shape.

Width :

Length :

Thickness :

Temperature :

Resistance: Ohms

The equation for resistance of a rectangular copper trace is :

$Resistance (\Omega) = \rho * \cfrac{L}{T*W}*(1+Tc*(Temp-25))$

where :
$\rho$ = Resistivity
L = Length
W = Trace width
T = Trace thickness (or height)
Tc = Temperature Coefficient
Temp = Temperature

This calculator used the following resistivity and temperature coefficient for copper :

Resistivity of copper : $1.7*10^{-6}\ \Omega \ cm$

Temperature Coefficient of copper : $3.9*10^{-3}\ \Omega / \Omega / \textdegree C$