Stepper motor speed calculator
Convert between stepper shaft speed and the pulse frequency a PLC or motion controller must output. Set steps per revolution (200 for a standard 1.8° motor) and the microstep divisor, then convert either direction.
Speed → pulse rate
Formula: f (Hz) = RPM × steps/rev × microstep / 60. A 1.8° motor has 200 steps/rev; with 8× microstepping that becomes 1,600 pulses per revolution — 120 RPM then needs 3,200 Hz.
Pulse rate → speed
Formula: RPM = f (Hz) × 60 / (steps/rev × microstep). Enter the pulse frequency the controller will output to find the resulting shaft speed.
PLCs and motion controllers output the step pulse train directly, so the frequency is what the program must produce for a target speed. AO Ctrl stocks stepper motors, drivers and the PLC output modules that generate the pulses:
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Frequently asked questions
How do I calculate the pulse frequency for a stepper motor RPM?
The tool uses f (Hz) = RPM × steps/rev × microstep / 60. A standard 1.8° motor has 200 steps/rev, so with 8× microstepping each revolution needs 1,600 pulses and 120 RPM requires 3,200 Hz. Enter your own steps/rev and microstep divisor to match your exact drive setup.
Why does microstepping change the required pulse frequency?
Microstepping subdivides each full step into smaller increments, so the controller must output more pulses per revolution: with 8× microstepping a 200-step/rev motor needs 1,600 pulses per revolution. The frequency therefore scales directly with the microstep divisor — double the microstepping and you double the pulse rate for the same shaft speed.
What RPM does a given pulse frequency produce?
The reverse conversion is RPM = f (Hz) × 60 / (steps/rev × microstep). With 3,200 Hz, 200 steps/rev and 8× microstepping the shaft turns at 120 RPM. This is the value a PLC high-speed output must generate for the motion controller to reach a target speed.