Motor Torque Calculator
Calculate motor torque instantly using power and speed. Enter input power in kW or HP and speed in RPM to get torque in N·m or lb·ft for any motor type.
motor torque from power and rpm calculator:
A Motor Torque Calculator helps determine the rotational torque a motor generates based on its power output and speed. Torque is the twisting force that produces rotation. The standard formula is T = (9550 × P) / N, where T is torque in newton-metres (N·m), P is motor power in kilowatts (kW), and N is rotational speed in revolutions per minute (RPM). Alternatively, in imperial units, T(lb·ft) = (5252 × HP) / RPM. This simple tool allows engineers to verify motor sizing, analyze shaft loads, and ensure mechanical compatibility with the driven equipment.
Work & Installation — Input to Output Summary
Work Principle: Motor torque represents the rotational effort produced by a motor’s shaft. It links electrical power and mechanical motion: higher torque means greater rotational force.
Installation Setup: Add inputs for Motor Power (choose unit: kW or HP) and Speed (RPM). Include dropdown for unit output selection (N·m or lb·ft).
Input: User enters motor power and speed.
Calculation:
For metric:
\( T(N.m) = \frac{9550 \times P_{kw}}{N_{RPM}} \)
For imperial:
\( T(Ib.ft) = \frac{5252 \times P_{HP}}{N_{RPM}} \)
Output: Display torque in selected units, optionally include reverse calculation (Power from Torque & RPM).
Interpretation: Higher torque indicates more load-handling capacity. Engineers use torque data to design couplings, belts, and shafts that can withstand applied mechanical forces.
Testing and Final Adjustments
Test the calculator with known motor ratings.
Example 1: Power = 5 kW, Speed = 1500 RPM → T = (9550 × 5) / 1500 = 31.83 N·m.
Example 2: Power = 10 HP, Speed = 1800 RPM → T = (5252 × 10) / 1800 = 29.18 lb·ft.
Verify that both unit systems yield correct results. Add form validation to prevent division by zero or blank entries.
Ensure output updates dynamically and rounds values neatly. Include a reset button and tooltips explaining each formula.
Test across browsers (Chrome, Edge, Firefox) and mobile devices for responsive layout. Finally, cross-check calculator
accuracy against standard motor datasheets. Ensure the UI clearly displays “Torque = … N·m” and optional “Convert to
lb·ft” link for user convenience.
