Use this handy calculator to find out how much torque your tractor is transmiting @ the pto shaft.
Enter known data into cells 1 & 2 and click CALCULATE. Results can be reset as often as you like by clicking the RESET buton.
When operating PTO driven implements it is best practice to run the implement at the maximum rated shaft speed.
The reason for this as you will discover when you use the torque calculator is that
when the PTO shaft speed falls below the rated rpm,
the PTO output torque will rise !
Tractor torque reserve characteristics will differ between makes and models, but it is possible that a tractor driving an implement in a heavy crop could drop the PTO speed from 1000rpm to 750rpm and still maintain useable horsepower.
To optimise your tractor horsepower, it is best ensure that your implement has a maximum torque rating is in excess of the tractor PTO output torque by at least 10%, otherwise prodouctivity will suffer due to constant slipping or tripping of the PTO overload clutch !