The article deals with the method of determining the number of parallel operating units and the number of the rotor rotations for each supercharger in the group by the economical criterion, taking into account the cost of fuel gas and the power of nitrogen oxides into the atmosphere. At the same time, limitations on technological parameters and conditions of uncertainty are taken into account, which are caused by inaccuracies of measurements and influence of uncontrolled parameters on the process of natural gas compression.