Lever Calculator
Enter load, effort arm and load arm to compute the effort force and mechanical advantage of a lever (torque balance).
Input Data
Results
At a glance:A lever is a rigid bar pivoting on a fulcrum that trades force for distance via torque balance. In equilibrium, the clockwise and counterclockwise torques are equal: F_effort × d_effort = F_load × d_load. Solving gives F_effort = F_load × (d_load/d_effort) and mechanical advantage MA = F_load/F_effort = d_load/d_effort. A longer load arm (or shorter effort arm) increases MA, letting a small effort lift a large load, at the cost of a longer effort stroke. Three classes differ by fulcrum/load/effort arrangement, but the torque balance is universal. This tool computes F_effort and MA from the forces and arm lengths.
Formula
Torque balance: F_e × d_e = F_L × d_L
MA = F_L/F_e = d_L/d_e
F_e = F_L·(d_L/d_e)
$$F_1 d_1 = F_2 d_2, \quad MA = \frac{d_1}{d_2} = \frac{F_2}{F_1}$$How to Use
- Enter the load force F_load (N).
- Enter the effort arm and load arm distances (m).
- The calculator returns the effort force and MA.
Case Studies
Crowbar
F_load = 1000 N, load arm = 0.1 m, effort arm = 1 m.
MA = 0.1/1 = 0.1? No: MA = d_load/d_effort = 0.1/1 = 0.1 → effort = 10000 N.
Wait: effort arm is longer, so MA = 0.1 (disadvantage). Use short load arm and long effort arm for MA>1.
FAQ
What is mechanical advantage?
MA = load/effort = load arm/effort arm. MA>1 means force is amplified (you move the effort farther). A crowbar may have MA of 5–10.
Does a lever create energy?
No. It conserves work: a larger force over a short distance (load) is balanced by a smaller force over a longer distance (effort). MA × effort distance = load distance inversely.
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References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.