Mechanical Advantage Calculator

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.

Class-one levers (fulcrum between effort and load) and class-two levers (load between fulcrum and effort) both follow the same arm-length ratio when friction is ignored. Wheelbarrows and crowbars are everyday examples.

Pulley systems add ideal MA by counting supporting rope segments — a block and tackle with four supporting strands gives ideal MA ≈ 4, though rope friction lowers real-world gain.

Worked example with defaults: 3 m effort arm, 0.5 m load arm → MA = 6. Lifting a 600 N load needs about 100 N effort at the handle, but the handle travels six times farther than the load rises.

A wheelbarrow is a class-two lever: the load sits between the wheel (fulcrum) and your hands (effort). Longer handles increase the effort arm without changing load arm much — the same MA formula applies even though the fulcrum is at the wheel axle. Wheelbarrow handles lengthen the effort arm while the wheel stays near the load — class-two lever geometry still follows effort ÷ load arm lengths.

Compound pulleys multiply ideal MA by the number of rope segments supporting the load, but each sheave adds friction. A 6:1 lever model here assumes rigid arms; real block-and-tackle systems often deliver 70–85% of ideal mechanical advantage. Block-and-tackle friction often leaves 70–85% of ideal MA — classroom six-to-one levers ignore bearing losses that real pulleys introduce.

With a 3 m effort arm and 0.5 m load arm, MA = 6 means lifting 300 N needs ~50 N effort. If friction consumes 20 N, you actually push 70 N — still easier than 300 N, but not the perfect sixfold reduction classroom physics predicts. At MA = 6, a 600 N load needs ~100 N ideal effort — 20 N friction means you feel ~120 N, still far below lifting 600 N directly.