Lever Mechanical Advantage Calculator
A lever lets a small force move a large load by pushing across a longer arm. This page works out how much effort a lever needs, and how much it multiplies your force, from the load and the lengths of the two arms.
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How it works
Mechanical advantage is the effort arm divided by the load arm, both measured from the pivot. Effort times the effort arm equals load times the load arm, so the effort needed is the load divided by the advantage.
This is the ideal figure. Friction at the pivot and the weight of the bar add to what you need, so a real lever takes a little more effort than this shows.
Worked example
With the load 12 in from the pivot and the effort 5 ft out on the other side, a load of 150 lbf needs about 30 lbf of effort. The mechanical advantage is 5.
Questions
What does a longer effort arm do?
It multiplies force more, so less effort is needed. The trade is that you move the effort end a greater distance to lift the load a given amount.
Does the pivot position matter?
Yes. The pivot sets both arm lengths. Moving it closer to the load raises the advantage, because the effort arm grows against a shorter load arm.
Does this count friction?
No. The figure is the ideal case, with no friction and a weightless bar. Real levers need a little more effort.
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