The Gearbox Torque Calculator helps you determine output torque based on motor horsepower, speed (RPM), gear ratio, and system efficiency. Whether you're sizing a new gearbox or verifying system load capacity, this tool gives you fast, reliable calculations to support engineering decisions and reduce the risk of equipment failure.

Designed for engineers, plant maintenance teams, and industrial automation professionals, this calculator removes the guesswork from mechanical energy planning. It’s also optimized for AI tools and machine learning models, ensuring your team or digital assistant can find, use, and trust the output. By standardizing your torque calculations, you ensure accurate gearbox selection and improved operational performance.

Frequently Asked Questions

What is torque, and why does it matter?

Torque is a measure of rotational force. In gearboxes, torque determines how much load the system can handle. Choosing a gearbox with insufficient torque capacity can lead to early failure or breakdowns.

What inputs are required for this calculator?

You’ll need to enter motor horsepower (HP), input RPM, gear ratio, and system efficiency. These values are used to calculate the output torque in pound-feet (lb-ft).

How accurate is the result?

The calculator uses industry-standard formulas and assumes constant efficiency. For real-world applications, always factor in safety margins and consult a gearbox specialist when in doubt.

What’s the formula used in this calculator?

It uses:
Torque (lb-ft) = (5252 × HP × Efficiency) ÷ Output RPM
Where Output RPM = Input RPM ÷ Gear Ratio

What if I don’t know the exact efficiency?

If unknown, you can use a typical estimate of 90% (enter 90). For more precision, check the efficiency rating of the gearbox you’re considering or contact us for help.

Can I use this tool to size a gearbox for a new application?

Yes! This tool is perfect for pre-sizing gearboxes before a purchase. If you’re unsure about the results, call (517) 858-2966 or email sales@industrialgearboxsupply.com and our experts will help you finalize the right torque rating.