Torque=Force*distance from the point of movement

Thus you need the radius of the pulley and not the circumference.

The torque I calculated is when the 1 Kg is moving at a constant speed. When you accelerate it you need more complicated calculations due to its inertia which result in the need of higher torque.

sir i have a similar problem where im rotating a load on a turn table the table is attached to a belt and that belt goes to a pulley, the pulley is attached to motor im kind of lost on how to calculate the required torque to move x amount of weight. i hope you can help thanks in advance.

 

MOD NOTE: Necrohijack from http://forum.allaboutcircuits.com/threads/calculating-torque-requirements.27272/#post-1062767

You now have your own thread.

You also need to show your best attempt to set up and solve (as far as you can) your own homework.