A method for determining the torque of a worm of a solid bowl worm centrifuge. The solid bowl worm centrifuge includes a rotatable drum and a rotatable worm, the rotatable worm being rotatable at a different rotational speed than that of the rotatable drum. The rotatable drum and rotatable worm are driven via a gear arrangement and a common single drive motor via at least one belt drive, a driving belt pulley, a driven belt pulley and a belt coupling the pulley. The method steps include determining a slip of the at least once belt drive and calculating a torque based upon the determination of the slip.