The advantage of levers, which relates effort and load (or input and output force), depends on how far away each are from the fulcrum. The mechanical advantage of a lever is increased when either the effort is moved further away from the fulcrum or the load is shifted closer to the fulcrum, or both. This idea of leverage can be expressed mathematically by:
Mechanical advantage of a lever = input distance / output distance
= effort arm / load arm
The distance between the load and fulcrum is called the Load Arm,
while the distance from the fulcrum to the effort is called the Effort Arm
The diagram for all the three classes of lever is being attached below for the reference.