Mechanical Advantage
Elementary School
Definition
The factor by which a machine multiplies an input force, found by comparing the output force to the effort applied. A machine with a high mechanical advantage lets a small force move a large load, though usually over a greater distance.
Worked examples
\(\)MA\( = \frac{\)Output Force\(}{\)Input Force\(} = \frac{600\,\)N\(}{50\,\)N\(} = 12\)
A machine with MA = 12 lets you apply 50 N to lift a 600 N load.
A lever with a 2 m effort arm and 0.5 m load arm
The ideal mechanical advantage is 2 ÷ 0.5 = 4, so a small push moves a larger load.
Common mistakes
- \(\)MA\( = \frac{\)Input Force\(}{\)Output Force\(}\) → \(\)MA\( = \frac{\)Output Force\(}{\)Input Force\(}\) Mechanical advantage compares what you get out to what you put in, not the reverse.
- A machine with MA = 5 multiplies both force and distance by 5 → MA = 5 multiplies force by 5, but you move the input a greater distance Machines trade distance for force; higher MA means the input moves farther than the output.
- Mechanical advantage has units like Newtons or meters → Mechanical advantage is a dimensionless ratio It is a comparison of two forces, so the units cancel out.
Where you'll use it next
You'll apply mechanical advantage when analyzing levers, pulleys, inclined planes, and gears in physics, and when studying efficiency and energy conservation in later science and engineering courses.
See also
Reviewed by Pat Cheng, M.Ed. — StudyPug Curriculum Lead · Last updated June 6, 2026