Calcometry

Mechanical Advantage Calculator

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Ideal MA = effort arm ÷ load arm for a simple lever.

Lever arms

Mechanical advantage

6 : 1

Ideal lever — no friction

Force multiplier

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Mechanical advantage

Mechanical advantage (MA) is how much a machine multiplies force. For an ideal lever, MA = effort arm length ÷ load arm length — the ratio of distances from the fulcrum.

MA greater than 1 means less force is needed to move the load, but the load moves a shorter distance. Real systems lose efficiency to friction; this is the ideal physics model.

Example: a 3 m effort arm and 0.5 m load arm gives MA = 6 — you need one-sixth the force, but must move the effort end six times farther.

Common questions

Does this include friction?

No. Real levers and pulleys have efficiency below 100%. This is an ideal classroom estimate.

Which arm is effort vs load?

Effort arm is from fulcrum to where you push or pull; load arm is from fulcrum to the weight or resistance.