Mechanical Advantage Calculator
A simple machine multiplies your effort, and mechanical advantage says by how much. Enter the load force the machine overcomes and the effort force you apply, both in newtons, to get the actual mechanical advantage as AMA = load / effort. Add an ideal mechanical advantage from the geometry, and the tool also reports efficiency as the actual value divided by the ideal, times 100.
How to find mechanical advantage
- Enter the load (output) force the machine overcomes in the Load force field, in newtons.
- Enter the effort (input) force you apply in the Effort force field, in newtons.
- Read the Mechanical advantage card, which shows AMA = load / effort.
- Optionally type a value in the Ideal advantage field to unlock the Efficiency card.
- Read Efficiency as a percent, then click Copy to save the AMA and efficiency line.
Examples
Lever lifting a load
load = 500 N, effort = 100 N
AMA = 5
Efficiency with friction
load = 500 N, effort = 100 N, IMA = 6
AMA = 5, efficiency = 83.333333333%
A machine that trades force for speed
load = 100 N, effort = 400 N
AMA = 0.25
Frequently asked questions
What is actual mechanical advantage?
Actual mechanical advantage (AMA) is the load force divided by the effort force, AMA = load / effort. It tells you how many times a machine multiplies your input force. A lever that lets 100 N lift a 500 N load has an AMA of 5.
How is efficiency calculated?
Efficiency is the actual mechanical advantage divided by the ideal mechanical advantage, times 100. Friction and other losses make the actual value lower than the ideal, so efficiency is below 100 percent. With AMA 5 and IMA 6 the tool reports 83.333333333 percent.
What is the difference between actual and ideal advantage?
Ideal mechanical advantage (IMA) comes from geometry alone, such as the ratio of lever arms or the number of rope segments, and it ignores friction. Actual mechanical advantage is measured from the real forces, so it is always equal to or less than the ideal value.
Where do I get the ideal mechanical advantage?
From the machine's dimensions, not from the forces. For a lever it is the effort arm divided by the load arm, for an inclined plane it is the slope length divided by the height, and for a pulley system it is the number of rope sections supporting the load. Enter that number to see efficiency.
Can mechanical advantage be less than 1?
Yes. A value below 1 means the machine trades force for speed or distance, so the effort force is larger than the load it moves. Fishing rods, tweezers and the human forearm all work this way, giving a fast, wide motion in exchange for extra input force.
What units should I use?
Use the same force unit for both load and effort. The fields are labeled in newtons, but pounds or kilograms-force also work as long as both boxes match, because mechanical advantage is a ratio and the units cancel out.
Why must the forces be greater than zero?
AMA divides load by effort, so a zero or negative force has no physical meaning here and would break the ratio. The tool requires both forces, and any ideal advantage you add, to be finite numbers greater than zero.
Can efficiency ever be above 100 percent?
Not for a real machine. If your calculated efficiency exceeds 100 percent, the ideal mechanical advantage you entered is too low or the measured forces are off. A genuine machine always loses some energy to friction, so real efficiency stays below 100 percent.
Is my data sent anywhere?
No. The calculation runs entirely in your browser, so the forces you enter never leave your device and nothing is uploaded to a server.
Learn more
- Actual vs ideal mechanical advantage
The difference between geometric IMA and measured AMA, how friction sits between them, and how their ratio defines a machine's efficiency.
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