Servo Motor Torque Calculator

Estimate running torque, acceleration torque, recommended motor torque, reflected inertia, and motor power for linear or rotary motion systems using load, radius, speed, acceleration time, gear ratio, efficiency, and safety factor.

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Good starting use case: use this for early servo sizing, concept design, and motion system screening before you dig into full reflected inertia models, detailed move profiles, gearbox backlash, gravity loading, regeneration, and vendor torque-speed curves.
Calculator

Estimate Servo Motor Torque

Estimate servo motor torque for rotary or linear motion systems using load, pulley or wheel radius, target speed, acceleration time, gear ratio, efficiency, and safety factor.

This calculator is useful for early servo sizing, motion system concept design, pulley-driven axes, conveyor-style drives, rotary indexers, and rough motor selection in industrial automation equipment.

Total Motor Torque = Running Torque + Acceleration Torque

Recommended Torque = Total Motor Torque × Safety Factor
Quick examples
Enter values and press Calculate.

Need help applying this to a real machine?

Get connected with a qualified automation integrator if you need help with servo sizing, motion system review, gear ratio decisions, or full machine concept development.

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This is a practical first-pass sizing calculator. Final servo selection should still consider true reflected inertia from all rotating components, move profile shape, gravity loads, gearbox backlash, duty cycle, shock loading, regenerative effects, and vendor torque-speed curves.

For this simplified model, the main load input is treated as a force-equivalent load in pounds. Use it for early estimating, not as a final motor sizing calculation.

What to check next

This tool gives a strong first-pass servo estimate, but real motor selection changes quickly once you include full inertia modeling, move profile shape, gravity effects, transmission stiffness, backlash, dwell pattern, and actual duty cycle at speed.

For real motion system design, this page usually works best alongside gear ratio, reflected load review, power checks, and vendor motor curves so you can confirm the chosen motor can survive the actual application.

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What this calculator gives you

  • Motor running torque
  • Motor acceleration torque
  • Total estimated motor torque
  • Recommended torque with safety factor
  • Reflected inertia at load and motor
  • Estimated motor power

Where this helps

Useful for early servo sizing, rotary indexer concepts, belt or pulley-driven axes, conveyors, direct-drive review, and screening whether a motion concept is even in the right range before detailed vendor sizing.

Common next checks

  • Full reflected inertia model
  • Move profile shape and duty cycle
  • Gravity load and holding torque needs
  • Gearbox backlash and stiffness
  • Vendor torque-speed curve limits

Need help with a servo application?

Submit your application details and I can review the request, help point you in the right direction, or connect you with someone better suited for deeper servo sizing support.

  • Motor sizing questions
  • Torque and acceleration review
  • Gear ratio questions
  • General motion application questions
This form is for application questions and general help requests. Final motor selection should still be confirmed with manufacturer tools and application-specific review.