Micro-reformers used for producing hydrogen with a high surface-to-volume ratio in small-scale fuel cells were investigated. To this end, scrutinizing and exploiting all areas of micro reformers is very important. Parallel micro-channels have shown good performance in eliminating dead volumes. Inlet/outlet configuration has great effect on the velocity distribution through micro-channels. In this study, four configurations (1 inlet/1 outlet on the same and opposite sides; 1 inlet/2 outlets on the same and opposite sides) were studied through simulation and 1 inlet/2 outlets on opposite sides were found to have the lowest velocity difference, hence having the best configuration. Simulations were carried out at 600 °C, 1 atm, with S/C=3 and feed flow rate of 100 mL/min. Three channel patterns (i.e., parallel, splitting-jointing and pin-hole) were compared in terms of Figure of Merit (FoM) and specific conversion. Parallel channel design revealed a high value of specific conversion to be about 5.36×10−5 𝑘𝑘𝑘𝑘𝐶𝐶𝐶𝐶4𝑚𝑚2⁄, while splitting-jointing and pin-hole were 5.33×10−5 and 4.91×10−5, respectively. Based on FoM, pin-hole design had a high value of 1.34×10−5 𝑘𝑘𝑘𝑘𝐶𝐶𝐻 4𝑚𝑚2.𝑃𝑃𝑃𝑃⁄, while the values of splitting-jointing and parallel designs were 0.037×10−5 and 1.28×10−5, respectively.