Electrical resistivity (volume resistivity) is a measure of how strong the material opposes the flow of electric current. It's the inverse of electrical conductivity.
Electric resistivity is calculated with the formula below:
Resistivity = R (Resistance of material) * A (Cross sectional area) / L (Length of the material)
SI unit of electrical resistivity is ohm meter. Other common units are ohm inch, microohm inch and ohm centimeter.