Calculate the effort force needed to move a load using mechanical advantage, lever, pulley, or ramp inputs, plus force reduction percentage.
Customize This Calculator
Build your own version. Describe what you want changed, added, or compared.
- All Physics Calculators
- All Force Calculators
- Lever Force Calculator
- AMA (Actual Mechanical Advantage) Calculator
- Resistance Force Calculator
- Wedge Force Calculator
Effort Force Formula
The effort force is the input force you apply to move or lift a load. The calculator uses different formulas depending on the selected method.
Mechanical Advantage Method
- EF = effort force
- L = load force
- MA = mechanical advantage
Lever Method
- EF = effort force
- L = load force
- LA = distance from the pivot to the load
- EA = distance from the pivot to where you apply the effort force
- MA = mechanical advantage
Pulley Method
- EF = effort force
- L = load force
- S = number of supporting rope segments
- MA = mechanical advantage
Ramp Method
- EF = effort force
- L = load force
- H = ramp height
- RL = ramp length
- MA = mechanical advantage
The main calculator uses a known mechanical advantage directly. The lever calculator compares the load arm and effort arm. The pulley calculator treats the number of supporting rope segments as the ideal mechanical advantage. The ramp calculator compares the ramp length to the ramp height. These formulas assume ideal conditions and do not include friction, pulley losses, rope stretch, or other real-world inefficiencies.
Common Mechanical Advantage Values
| Setup | Typical Ideal MA | Effort Force Compared With Load |
|---|---|---|
| No mechanical advantage | 1 | Same as the load |
| 2:1 lever, pulley, or ramp | 2 | One-half of the load |
| 4:1 lever, pulley, or ramp | 4 | One-fourth of the load |
| 5:1 ramp | 5 | One-fifth of the load |
Force Unit Conversions
| Unit | Equivalent | Common Use |
|---|---|---|
| N | 1 newton | SI force calculations |
| kN | 1 kN = 1,000 N | Large loads |
| lbf | 1 lbf ≈ 4.44822 N | US customary force calculations |
Example Problems
Example 1: Effort force with mechanical advantage
You need to move a 600 N load with a mechanical advantage of 3.
The required effort force is 200 N.
Example 2: Effort force for a lever
A lever lifts a 500 N load. The load is 0.4 m from the pivot, and the applied effort is 1.6 m from the pivot.
The required effort force is 125 N. The mechanical advantage is 1.6 / 0.4 = 4.
FAQ
What is effort force?
Effort force is the force you apply to a machine or tool to move a load. In a lever, it is the force applied to one side of the pivot. In a pulley, it is the pulling force on the rope. On a ramp, it is the force needed to push or pull the load up the incline.
Why is the real effort force sometimes higher than the calculated value?
The calculator uses ideal mechanical advantage. Real systems have friction, bending, pulley bearing losses, rope drag, surface resistance, and other inefficiencies. Because of that, the actual force you need may be higher than the calculated value.
Does a higher mechanical advantage always make lifting easier?
A higher mechanical advantage lowers the required effort force, but it usually increases the distance you must move. For example, a 4:1 pulley may require about one-fourth the force, but you may need to pull about four times as much rope in an ideal system.
