Motor Speed Calculator
Calculate your motor speed with our free online tool. Get accurate results instantly. No signup required.
What Motor Speed Calculator does
The Motor Speed Calculator on Number Convert determines the rotational speed of AC motors using supply frequency and pole count. Users enter the power frequency in hertz and the number of motor poles to receive synchronous speed in RPM. For induction motors, an optional slip percentage adjusts the result to estimate actual loaded shaft speed. The tool also includes a loading calculator and displays how frequency, pole count, and slip interact to affect machine timing and equipment performance. Results appear instantly after input, and no registration is required to use the service.
How to use the Number Convert Motor Speed Calculator
- 1
Enter the power frequency in hertz
- 2
Input the number of motor poles
- 3
Optionally adjust slip percentage for induction motors
- 4
View the calculated synchronous or actual shaft speed in RPM
Best for
Engineers, mechanics, and DIY enthusiasts who need to quickly determine motor RPM from electrical frequency and pole configuration without manual calculation.
Limitations
- Results are estimates based on standard motor formulas
- Slip values must be entered as whole numbers (e.g., 3 for 3%)
- Designed for AC motors; does not cover DC motor speed calculations
Motor Speed Calculator FAQ
- How do I calculate the synchronous speed of a motor?
- Enter the supply frequency in hertz and the number of poles; the tool applies the formula Ns = 120f / P to return RPM.
- What is slip and how does it affect the result?
- Slip is the difference between synchronous speed and actual shaft speed under load; entering a slip percentage adjusts the RPM downward for induction motors.
- Can this tool calculate DC motor speed?
- No, the calculator is designed for AC motors using frequency and pole count; DC motor speed requires different inputs like voltage and load.
- Do I need to create an account to use the Motor Speed Calculator?
- No, the tool is free to use and does not require signup or registration.