The D-Rating Calculator assists users in determining the minimum required D-rating for fifth wheel and drawbar couplings across various heavy vehicle combinations, in accordance with AS 4968.1:2023 and AS 2213.1:2022.
Select the coupling category and vehicle configuration, then enter the applicable mass values. The calculator determines the minimum required D-rating in kilonewtons (kN).
This tool is intended as a practical assessment aid only. Users are responsible for ensuring compliance with all applicable regulatory, manufacturer and engineering requirements.
