Pulley Mechanical Advantage Calculator
Mechanical advantage and effort force for a pulley system.
Enter your values
ⓘ Live results
Results
- Ideal mechanical advantage
- 4:1
- Ideal effort force
- 125 N
- Actual effort force (with friction)
- 147.1 N
- Rope pulled per metre lifted
- 4 m
Quick answer
Mechanical advantage equals the number of rope segments supporting the load.
MA = number of supporting ropes; effort = load/MA
How to use the Pulley Mechanical Advantage Calculator
- 1Enter the load weight to lift.
- 2Count how many rope segments support the moving pulley block.
- 3Adjust efficiency to account for pulley friction.
Worked example
Using the values the calculator loads with:
Inputs
- Load weight500 N
- Supporting rope segments4
- System efficiency85 %
Results
- Ideal mechanical advantage4:1
- Ideal effort force125 N
- Actual effort force (with friction)147.1 N
- Rope pulled per metre lifted4 m
Frequently asked questions
Why pull more rope than the load moves?
More rope segments mean less force but proportionally more rope must be pulled — energy in equals energy out.
What efficiency should I use?
Well-lubricated pulley blocks are around 90-95% per pulley; friction compounds with more pulleys.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.