This paper focuses on data reduction of friction factor of compressible fluid flowing through micro-channels. The both pressure and temperature are required to calculate the friction factor of compressible flow. Therefore, in the past data reduction of many experiments, the friction factors have been obtained under the assumption of isothermal flow since temperature measurement of compressible flow in micro-channels is quite difficult due to the experimental technique limitation. The authors find that the temperature of the fluid can be obtained from the pressure under the assumption of one dimensional flow in an adiabatic channel (Fanno flow). In this paper, the temperatures obtained by our proposed equation are compared with results of numerical simulations and friction factors are also compared. (C) 2014 Elsevier Ltd. All rights reserved.