Mechanical Advantage Calculator — Simple Machines
Find the ideal mechanical advantage (MA) of any classic simple machine — lever, inclined plane, wheel and axle, or pulley — and see how much it multiplies your applied force.
Machine type
m
m
N
Ideal (frictionless) ratio of output force to input force
- 1
Effort arm length
2 m - 2
Load arm length
0.5 m - 3
MA = effort arm ÷ load arm
2 ÷ 0.5 = 4
How does this calculator work?
Mechanical advantage = output force / input force, calculated from geometry alone (no friction). For levers use effort arm / load arm; for inclined planes use length / height; for pulleys count load-side rope segments. MA > 1 multiplies your applied force; MA < 1 gives a speed advantage instead.
Formula
How this is calculated
Mechanical advantage describes how much a simple machine multiplies an input force. An MA of 4 means you can lift a 400 N load with only 100 N of effort — the machine does the rest. This is always the ideal (theoretical) MA, calculated purely from geometry and assuming zero friction; real machines have efficiency losses that reduce the actual force gain.
For a lever, MA equals the ratio of the effort arm to the load arm, where both arms are measured from the fulcrum. An effort arm of 2 m and a load arm of 0.5 m gives MA = 4. For an inclined plane, MA = slope length / vertical height — a long, gradual ramp needs far less force than lifting straight up. Wheel-and-axle systems (steering wheels, winches) multiply force by the wheel-to-axle radius ratio. A movable pulley system has MA equal to the number of rope segments supporting the load.
MA < 1 is also possible and useful: a fishing rod or bicycle gear cranked for speed trades force for distance/speed. The calculator shows the MA on a number line so you can instantly see whether and by how much force is being multiplied.
Frequently asked questions
Friction in the pivot, surface roughness on an incline, or rope stiffness in a pulley all absorb some of the input force. The actual MA = ideal MA × efficiency (typically 60–95% for real machines). This calculator gives the frictionless ideal; multiply by your estimated efficiency for a realistic figure.
Yes. When MA < 1 the machine amplifies speed or distance instead of force — a baseball bat, fishing rod, or racing bicycle gear. You apply more force than you get out, but the output moves faster or farther. Whether that trade-off is useful depends on the task.
Count only the rope segments that directly support the moving (load) pulley — not the free end held by the operator. A single movable pulley with one free end has MA = 2; a block-and-tackle with four load-side segments has MA = 4.
TG we-Calculate Editorial Team. (2026). Mechanical Advantage Calculator — Simple Machines [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/mechanical-advantage-calculator
TG we-Calculate Editorial Team. "Mechanical Advantage Calculator — Simple Machines." TG we-Calculate. 2026. https://we-calculate.com/calculator/mechanical-advantage-calculator.
TG we-Calculate Editorial Team, "Mechanical Advantage Calculator — Simple Machines," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/mechanical-advantage-calculator
@misc{wecalculate_mechanical_advantage_calculator, title = {Mechanical Advantage Calculator — Simple Machines}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/mechanical-advantage-calculator}}, year = {2026}, note = {TG we-Calculate} }
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