Usually the resistance change in metals is mostly due to the change of geometry resulting from applied mechanical stress. However, even though the piezoresistive effect is small in those cases it is often not negligible. In cases where it is, it can be calculated using the simple resistance equation derived from Ohm's law;
:where
: Conductor length [m]
:A Cross-sectional area of the current flow [m²]

Some metals display piezoresistivity that is much larger