PCB Trace Resistance Calculator January 24, 2006
This online web calculator finds the resistance of copper PCB traces (a.k.a. tracks) of given width, thickness, length, and temperature. It can also be used for copper bars (e.g. bus bars). Several choices of common units are available. Enter the Width and Thickness below. Optionally, enter the Temperature and Length, or just leave the default values. (To find the needed trace width based on current, see the PCB Trace Width Calculator.)
May 17, 2006 - Added (lateral) thermal resistance calculations.
January 18, 2007 - Clarified equations.
- Resistance per foot can be calculated by entering a length of 1 foot.
- If cookies are enabled, the form will return to its previous state upon your next visit, so your unit preferences etc. will persist.
|Thermal Resistance||Deg. C/Watt|
Resistance = Resistivity*Length/Area*(1 + (Temp_Co*(Temp - 25))
Where, Area = Thickness*Width
A copper Thickness of 1 oz/ft^2 = 0.0035 cm
Copper Resistivity = 1.7E-6 ohm-cm
Copper Temp_Co = 3.9E-3 ohm/ohm/C
Thermal_Resistance = Thermal_Resistivity*Length/Area
Copper Thermal_Resistivity = 0.249 cm-K/W (at 300K)