Pulley Mechanical Advantage Calculator

About this calculator

For an ideal pulley system, mechanical advantage equals the number of rope segments supporting the moving load — not the number of pulleys. A single fixed pulley has an MA of 1 (it only changes direction), while a block-and-tackle with two segments supporting the load doubles the force, and effort required = load ÷ MA when friction is ignored.

Riggers and crane operators use this to plan how many parts of line a lift needs, sailors size block-and-tackle purchases on halyards and mainsheets the same way, and it's a standard physics-class demonstration of simple machines trading distance for force — pulling more rope through the system to lift a heavier load with less effort.