Enter the effort force and lever force into the calculator to determine the force at the fulcrum of a lever at equilibrium.

Fulcrum Force Formula

The following equation is used to calculate the Fulcrum Force.

FF = EF + LF
  • Where FF is the fulcrum force (N)
  • EF is the effort force (N)
  • LF is the lever force (N)

To calculate the fulcrum force, sum together the effort force and the lever force.

What is a Fulcrum Force?


A fulcrum force is the total force seen at the fulcrum of a lever/beam when the beam is at equilibrium. This means that the moment about the fulcrum equals 0, even though the weights and forces on either side may not be equal.

How to Calculate Fulcrum Force?

Example Problem:

The following example outlines the steps and information needed to calculate the Fulcrum Force.

First, determine the lever force. Multiply the mass of the object by gravity yields an effort force of 50 N.

Next, determine the lever force. Knowing the effort force and distances, the lever force is calculated to be 150N.

Finally, calculate the fulcrum force using the formula above:

FF = EF + LF

FF = 50 + 150

FF = 200 N


What is the principle behind a lever and fulcrum system?

The principle behind a lever and fulcrum system is based on the law of the lever, which states that when a lever is in equilibrium, the torque produced by the effort force on one side of the fulcrum is equal to the torque produced by the load force on the other side. This principle allows for the multiplication of force, enabling a smaller effort force to move a larger load.

How does the distance from the fulcrum affect the fulcrum force?

The distance from the fulcrum affects the fulcrum force through the concept of mechanical advantage. The longer the distance from the fulcrum to the point where the effort force is applied (effort arm), compared to the distance from the fulcrum to the load force (load arm), the less effort force is needed to balance or move the load. This is because the torque (force times distance) on both sides of the fulcrum needs to be balanced for the lever to be in equilibrium.

Can the fulcrum force be negative or zero?

The fulcrum force itself is a conceptual representation of the total force acting at the fulcrum point and is typically considered as a positive value indicating magnitude. However, in a theoretical sense, if the effort force and lever force were to act in opposite directions with equal magnitude, the net fulcrum force could be considered zero, indicating a state of perfect balance without any movement. A negative value would not typically be used to describe fulcrum force, as forces are generally described in terms of magnitude and direction relative to the system being analyzed.