Calculate torque, speed, and power with engineering inputs. Review formulas, exports, and examples quickly online. Make rotating equipment checks with clear dependable results today.
| Case | Power (kW) | Speed (RPM) | Torque (N·m) | Use Case |
|---|---|---|---|---|
| Example 1 | 2.20 | 1440 | 14.59 | Small pump motor |
| Example 2 | 5.50 | 1450 | 36.24 | Fan drive |
| Example 3 | 11.00 | 960 | 109.43 | Mixer duty |
| Example 4 | 15.00 | 2900 | 49.40 | High speed shaft |
The main engineering relation is:
Power (kW) = Torque (N·m) × RPM / 9550
From this equation:
Torque (N·m) = 9550 × Power (kW) / RPM
RPM = 9550 × Power (kW) / Torque (N·m)
Angular velocity is calculated as:
Angular Velocity (rad/s) = 2 × π × RPM / 60
Output shaft values use efficiency and gear ratio:
Output Power = Motor Power × Efficiency
Output Speed = Motor RPM / Gear Ratio
Output Torque = Motor Torque × Gear Ratio × Efficiency
Design Torque = Output Torque × Service Factor
A kW torque calculator helps engineers connect power, speed, and shaft load. These values shape motor selection, gearbox planning, and machine reliability. Power alone does not show turning force. Torque reveals the real twisting demand on the shaft. RPM shows how fast the shaft rotates. Together, they describe mechanical output more clearly.
This calculator supports motor sizing, conveyor design, pump systems, mixers, fans, crushers, and rotating process equipment. It also helps maintenance teams compare nameplate power with real torque demand. Design teams often need quick checks during procurement or troubleshooting. A fast kW torque calculation reduces guesswork and improves technical communication between electrical and mechanical teams.
Many real machines do not operate at direct motor speed. A gearbox changes output RPM and torque. Lower output speed usually increases output torque. However, losses inside the drive reduce usable power. That is why efficiency is included here. Service factor is also important. It gives a design margin for shock loads, variable duty, and harsher working conditions.
The result section reports motor power, speed, torque, angular velocity, output power, output speed, output torque, and design torque. This wider view makes the tool more practical than a basic formula box. It helps you compare direct drive and geared systems quickly. It also supports reporting because the CSV and PDF options save structured results.
Use this calculator early in design and again during verification. Confirm that torque matches the load profile. Check whether speed reduction changes torque enough for the application. Review the service factor before freezing equipment choices. Simple checks like these can prevent undersized drives, excess heat, shaft stress, and early component failure.
kW means kilowatts of mechanical power. It is the power level delivered by the motor or shaft in the calculation.
Different industries use different units. N·m is standard in SI work. lb-ft and kgf-m help when legacy specifications or vendor sheets use other systems.
Yes. Choose the speed mode. Enter power in kW and torque in N·m. The calculator returns the required motor speed in RPM.
The gear ratio lowers output speed and raises output torque. A ratio greater than one means the output shaft turns slower than the motor shaft.
Efficiency accounts for drive losses. Real gearboxes and transmissions waste some power. That reduces the output power and output torque available at the driven shaft.
Service factor adds a design margin. It helps engineers size equipment for shock, start-stop duty, uneven loading, and tougher operating conditions.
Yes. It helps compare torque demand with motor capability. It is also useful for validating gearbox output and checking if a selected drive is sensible.
No. It is a fast engineering calculator. Final design should still consider duty cycle, thermal limits, starting torque, overloads, standards, and manufacturer data.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.