The electron mobility has been obtained in InSb by the Monte Carlo simulation technique for different applied electric fields. The mobility values have then been expressed empirically by simple power law relationship. It is observed that the mobility values calculated by using these simple power law relations yield values that show agreement within 5% with those obtained from the detailed Monte Carlo simulation technique. It is concluded that these empirical relations can be used effectively for a quick estimation of mobility, as a check on experiments and also as sufficiently accurate formulae for simulation and modelling purposes. © 2005 IACS.