Physics
Instant, private, and free
Linear Actuator Force Calculator.
Calculate ideal screw-actuator force from torque, lead, and efficiency.
Set your values
Results update as you type.
Results update automatically as you type.
Use Cases
Designing a linear actuator system
Engineers can use this calculator to estimate the force output of a screw-driven actuator based on motor torque and screw specifications, helping in component selection.
Example: If you have a motor with 2 N·m torque, a screw lead of 0.005 m/rev, and 90% efficiency, the force is about 2261 N.
Educational physics demonstrations
Students and educators can explore the relationship between torque, lead, and force in mechanical systems, reinforcing concepts of mechanical advantage.
Example: Vary the lead from 0.01 to 0.001 m/rev to see how force increases tenfold.
Frequently Asked Questions
- How is linear actuator force calculated?
- The force is calculated using the formula: Force = (2 * π * Torque * Efficiency) / Lead. You input motor torque in N·m, screw lead in m/rev, and efficiency as a decimal (e.g., 0.9 for 90%). The calculator outputs the ideal force in Newtons.
- What does screw lead mean?
- Screw lead is the linear distance the actuator moves per one complete revolution of the screw. It is measured in meters per revolution (m/rev). A smaller lead gives higher force but lower speed, while a larger lead gives lower force but higher speed.
- Why is efficiency important in this calculation?
- Efficiency accounts for losses due to friction and other factors in the screw mechanism. Real-world actuators are not 100% efficient, so using an efficiency value (e.g., 0.85) gives a more realistic force estimate. The calculator uses efficiency as a multiplier in the formula.
Tips & Common Mistakes
Tips
- Ensure torque is in N·m and lead is in m/rev. Convert units if necessary (e.g., from lb-ft to N·m).
- Efficiency should be between 0 and 1. Typical screw efficiencies range from 0.2 to 0.9 depending on type (ball screw vs. lead screw).
- For a quick estimate, use 0.9 for ball screws and 0.5 for lead screws, but check manufacturer data for accuracy.
- Remember that this calculator gives ideal force; actual force may be lower due to additional losses like bearing friction.
Common Mistakes to Avoid
- Using lead in mm/rev instead of m/rev. Always convert to meters (e.g., 5 mm = 0.005 m).
- Entering efficiency as a percentage (e.g., 90) instead of a decimal (0.9). The calculator expects a value between 0 and 1.
- Confusing torque with power. Torque is a force applied at a distance, not the motor's power rating.
Last updated: August 13, 2026