This study aimed to improve the method for determining the position of the center of gravity for agricultural tractors. Methods: The proposed method uses trigonometric functions and coordinate transformation. Data were measured according to the ISO 789-6 test procedures for the center of gravity of agricultural tractors. The height calculated using the proposed method was compared with that determined from an AutoCAD drawing. To find the center of gravity of the tractor, the algorithm for finding the intersection of the two lines was used. Results: The vertical height from the ground to the center of gravity is 682.06 mm. The vertical coordinates obtained from the calculation and the drawing were the same. Conclusions: The developed method uses trigonometric and polar coordinate transformation. The method was compared and verified with the AutoCAD drawing results. The results indicate that users can apply this developed method instead of the plotting method which is an inconvenient and time-consuming. Further, users can program Microsoft Excel to easily determine the vertical coordinate. In addition, researchers will propose this method to the ISO as a standard method for determining the center of gravity in accordance with ISO 789-6.