Mechanical Advantage Calculator
Enter the load force and the effort force and get the mechanical advantage — the single number that tells you how many times a lever, pulley, or ramp multiplies the force you put in.
What is mechanical advantage?
Force out over force in, one clear number
Mechanical advantage (MA) is how much a machine multiplies the force you apply: the load force it moves divided by the effort force you supply. A lever, pulley, gear train, or ramp lets you trade a small push over a long distance for a large push over a short one — and the mechanical advantage is the number that captures that trade. It is the go-to figure whenever you size a tool or simple machine for a heavy job.
Enter the load force and the effort force to get the mechanical advantage instantly.
One short formula: divide the load force by the effort force.
MA = load force ÷ effort forceBecause mechanical advantage is one force divided by another, the units cancel and the answer is a plain number — a ratio, not a force. A result of 5 means the machine outputs five newtons of load force for every newton of effort you supply, as long as both forces are entered in the same unit.
Suppose a machine lifts a load that needs 500 newtons while you push with 100 newtons of effort.
Note the load and effort forces
The load force is 500 N and the effort force you apply is 100 N — keep both in the same unit so the ratio is unitless.
Divide load by effort
500 ÷ 100 = 5 — the load force per unit of effort force.
Read the mechanical advantage
5 — the machine multiplies your input force five times.
The single mechanical-advantage figure tells you exactly what the machine does for you. When MA is greater than 1, the machine multiplies force: a crowbar, a block-and-tackle pulley, or a gentle ramp lets a small effort move a large load, which is the whole point of a simple machine. When MA equals 1, the machine multiplies nothing — it only changes the direction of the force, like a single fixed pulley that lets you pull down to lift up. When MA is less than 1, the machine trades force for speed or distance: a bicycle in a high gear, or your forearm acting as a lever, moves the output further and faster than the input while demanding more force. One important caveat is that the value you compute here is the actual, force-ratio mechanical advantage. In a perfect frictionless machine it would equal the ideal geometric advantage set purely by the lengths or radii, but real friction always bleeds off some output force, so the actual mechanical advantage is usually a little below the ideal value.
The formula is exact, but keep a couple of practical points in mind.
Same units, steady forces, and friction
The load and effort forces must be in the same unit, or the ratio is meaningless. The formula also assumes a single steady pair of forces — it does not capture how the advantage changes through the stroke of a varying lever or cam. And because it uses the forces you actually measure, the result already includes friction losses, so it can sit below the ideal geometric value a frictionless machine would reach.