How do you calculate the effort of a pulley?

The general effort force equation for block and tackle to raise or pull a load can be expressed as

S = F / μn

where

S is the effort force,

F is the load force (often the weight of the object to be moved),

μ is the mechanical efficiency of the system (1 in an ideal, massless, frictionless system of pulleys), and

n is the number of ropes between the sets of pulleys.