The threshold voltage of a MOSFET in strong inversion is called the extrapolated threshold, VT0. This voltage is extracted by connecting the source to the substrate thus avoiding the effect of the reverse biased source – substrate junction ( VBS ). In order to calculate the threshold with body effect an equation is used ( hand calculations). This formulation includes constants such as VT0, GAMMA ( body effect parameter) and the surface potential in strong inversion ( 2phiF). A calculator to do this, written in javascript, has been released by Signal Processing Group Inc. and is available on the SPG website. Please visit for this, as well as other information.