measure of the force amplification achieved by using a tool, mechanical device or machine system

Mechanical advantage (also written as MA in formulas) is the factor by which a machine multiplies force. The mechanical advantage of a machine can be used to find out how well a machine works and whether it can perform a particular job.

Machines that multiply force.

The mechanical advantage of a machine is the ratio of the load (the resistance overcome by a machine) to the effort (the force applied).

${\displaystyle MA={\frac {\text{output force}}{\text{input force}}}}$

For an ideal (without friction) mechanism, it is also equal to:

${\displaystyle MA={\frac {\text{distance over which effort is applied}}{\text{distance over which the load is moved}}}}$

There is no unit for mechanical advantages since the unit for both input and output forces cancel out.