Calculator Inputs
Formula Used
For a class 2 lever, the load is between the fulcrum and the effort. The torque balance is:
Effort × effort arm × sin(effort angle) = Load × load arm × sin(load angle) + lever weight × center arm × sin(weight angle)
Ideal mechanical advantage is the effective effort arm divided by the effective load arm. Actual mechanical advantage is load divided by effort.
Efficiency = (actual mechanical advantage ÷ ideal mechanical advantage) × 100
How to Use This Calculator
- Select what you want to solve.
- Choose the force unit and length unit.
- Enter known load, effort, and arm values.
- Keep angles at 90 degrees for perpendicular forces.
- Add lever weight and center arm when the lever is heavy.
- Press Calculate and read the result below the header.
- Use the CSV or PDF buttons to save the result.
Example Data Table
| Case | Load | Effort Arm | Load Arm | Ideal Effort | Ideal Advantage |
|---|---|---|---|---|---|
| Wheelbarrow style | 600 N | 1.20 m | 0.30 m | 150 N | 4.00 |
| Short handle | 600 N | 0.90 m | 0.30 m | 200 N | 3.00 |
| Load moved outward | 600 N | 1.20 m | 0.40 m | 200 N | 3.00 |
About the Class 2 Lever Calculator
A class 2 lever places the load between the fulcrum and the effort. This layout gives useful force gain. A wheelbarrow, nutcracker, bottle opener, and toe raise are common examples. The calculator models that simple idea with more control. It lets you solve for effort, load, arm length, or advantage. It also includes force angle and lever weight. These details help when the push is not perfectly square to the arm.
Why the inputs matter
The load arm is measured from the fulcrum to the load. The effort arm is measured from the fulcrum to the applied effort. In a true class 2 lever, the load arm is shorter than the effort arm. That is why the effort can be lower than the load. The tool checks this relationship. It also shows the velocity ratio. A larger ratio usually means less effort. It also means the effort point must move farther.
Practical use cases
Use this calculator when planning handles, pedals, lifting bars, simple shop aids, or classroom examples. It can estimate the push needed before you build a part. It can also compare several layouts. Small changes in the load position may change the needed effort a lot. A longer handle can reduce force. A heavier handle can add extra resisting torque. The center of gravity input helps include that effect.
Reading the result
The result section shows the solved value first. It then lists torque values, mechanical advantage, efficiency, and balance error. A small balance error means the entered values match the lever equation. Efficiency compares actual force gain with ideal geometry. Real systems lose force through bending, friction, poor contact, and angle error. For safe work, treat the answer as an estimate. Add a safety factor when people, tools, or heavy loads are involved. Keep measurements consistent. Check arms from the same fulcrum point. Use perpendicular distances when possible. Recalculate after changing the design.
Exporting and records
After calculation, use the export buttons to save a short record. The CSV file helps spreadsheets. The PDF file helps reports. Example data below gives a quick check. You can replace those values with your own trial measurements. Save each version before changing geometry.
FAQs
What is a class 2 lever?
A class 2 lever has the fulcrum at one end, effort at the other end, and load between them. This layout usually gives force advantage because the effort arm is longer than the load arm.
Why is the load arm shorter?
The shorter load arm reduces the torque created by the load. That means a smaller effort can balance a larger load when the effort arm is longer.
What angle should I use?
Use 90 degrees when the force acts perpendicular to the lever arm. Use the actual angle when the push or load is slanted from the arm.
Does lever weight matter?
It matters when the lever is heavy or long. Enter the lever weight and its center arm to add its resisting torque to the calculation.
What is ideal mechanical advantage?
Ideal mechanical advantage compares effective arm lengths. It ignores friction, bending, and contact losses. It is the best possible force gain for the geometry.
What is actual mechanical advantage?
Actual mechanical advantage is load divided by effort. It uses measured or calculated forces, so it can show losses that ideal geometry does not include.
Why can efficiency exceed 100 percent?
That usually means one input is inconsistent. Recheck the effort, load, arm lengths, and angles. Real levers cannot deliver more than ideal performance.
Can I use inches and pounds?
Yes. Choose pound-force for force and inches for length. The calculator converts internally and shows the final answer in your selected units.