The selection of correctly matched machinery implements involves both technical and economic data. For solution to more complex machinery management problems, the annual machinery costs are calculated using the actual cash flows, which occur each year. The calculation of annual costs of machine ownership is based on three types of cash flow; capital cost repayable by equal mortgage installments, recurring annual repair and insurance changes and income from selling the machine. For this reason the aim of study is elicitation of modeling for calculating the total cost of tractors and agricultural machinery under suggest Egyptian conditions. The concluded results clear that the present annual cost of machine ownership is substantially altered by tax relief and allowances. By applying a (0%, 30% and 60%) tax on calculation of tractor annual cost, the present annual cost was reduced from to 8374.1Cv to 7519.3 Cv. While, using the conventional methods the present annual cost was 9228.9 Cv. The present approach yields an intermediate cost figure within the range spanned by the present annual ownership costs with and without tax.