Reference Designer Calculators



OZ to mils(inch) Convession


The formula converts Copper Plating Weight in oz to thickness in inch. This is useful for PCB designer willing to know the thickness corresponding to a copper plating weight to inch or mils.

The copper in a PCB is rated in ounces, and represents the thickness of 1 ounce of copper rolled out to an area of 1 square foot. For example a PCB that uses 1 oz. copper has a thickness of 1.4mils.

Following is the formula cpw ( in oz) to thickness ( in mils) conversion.

Thickness(in oz) = 1.37 * thickness (in mils)

Following is the formula thickness ( in mils) to cpw( in oz) conversion.

t ( in mils) = t ( in oz)/1.37



  (Thickness in mils) :
  (CPW in oz)


If you are interested in derivation, you can use the following facts to convert the Cu / ft2 to mils

1 oz = 28.35 g = 0.02835 kg

Area = 1 ft2 = (0.304 m)2 = 0.0924 m2

Density (Cu pure) rho = 8950 kg / m3