⚡ VFD Synchronous Speed Calculator

Calculate motor synchronous speed from VFD frequency

Synchronous Speed
1800
RPM
⚠️ Important Note:
*The motor will operate slightly slower than this due to slip. Typical slip is 3-5% for induction motors at full load.
Formula:
Synchronous speed = 2×LF / Poles
Where: LF = Line Frequency (Hz), Poles = number of motor poles
What is Synchronous Speed?
The synchronous speed is the theoretical speed at which the magnetic field rotates. It's determined by the AC frequency and the number of motor poles. Actual motor speed (rotor speed) is slightly less due to slip, which is necessary for the motor to develop torque.
Quick Reference:
Poles @ 60 Hz @ 50 Hz
2 Poles 3600 RPM 3000 RPM
4 Poles 1800 RPM 1500 RPM
6 Poles 1200 RPM 1000 RPM
8 Poles 900 RPM 750 RPM
About Motor Slip:
Slip is the difference between synchronous speed and actual rotor speed, expressed as a percentage. For a standard induction motor: Slip (%) = (Nsync - Nactual) / Nsync × 100

A 4-pole motor at 60 Hz (1800 RPM sync) with 3% slip runs at approximately 1746 RPM.