To calculate the effort required to lift the load we divide the load by the number of ropes (do not count the rope that goes to the effort). The image on the right shows a four pulley system. The person lifting the 200kg load experiences a pull equal to only 50kg (200kg/4).

Using the four pulley system on the right, the person certainly experiences an advantage. We call this advantage the mechanical advantage and is calculated by dividing the load by the effort (load/effort). The pulley system offers a mechanical advantage of 4.