The objective of this work was to develop a computing system aiming to aid both the technicians and managers of the branch of load transportation to calculate the cost of the kilometer covered by load trucks as well as to perform the yield analysis of a transporting enterprise. The computing system was developed by utilizing Microsoft Excel®. The system possesses a accounting plan which enables to the user the cadastering of all the expenditures and incomes. In addition, it allows the cadastering of the initial investments of the movables and improvements acquired, aiming to include the fixed costs concerning the depreciation. The system possesses abstract-spreadsheet which informs the user the result of the final of the period of each truck and also the general abstract which shows the analysis of the profitability of all the transporting enterprise. The system developed enables to perform simulations involving a number of parameters and mainly it determines the cost of the covered kilometer, coming to be one important tool which helps the management of the enterprise, by furnishing indicators of technical, financial and economic performance.