This research is mainly conducted to study the farm machinery economic evaluation and selection the optimum tractor and implement sizes. The connection between draft and fuel consumption relative to the operation cost and machine selections is identified as a present idea to evaluate the tractor-plough operation. Therefore, the objective of this research is to use the economical method to select the tractor and plough for the tillage operation depending on the tractor-plough roperties. For this reason the tractor tire specifications and the chisel plough properties are used by the visual basic program to aculate the fuel cost/fed at different tractor power, forward speed and plough width. The results showed that the suitable tractor can be used to tillage operation of 47.81 kW for all plough width and at different forward speed.