Stepper Motor Step Angle

Formula

Description

A stepper motor moves in discrete angular increments. The base step angle depends on the motor construction: 200 steps/rev (1.8°/step) is the most common, with 400 steps/rev (0.9°/step) for higher precision applications. Microstepping divides each full step into smaller increments by controlling the current ratio between adjacent coil phases. Common microstep settings are 2 (half-step), 4, 8, 16, 32, 64, and 256. While microstepping increases positioning resolution, the actual angular accuracy at microstep positions is limited by motor construction tolerances.

Variables

• θ — Angular displacement per microstep (degrees)
• steps — Full steps per revolution (typically 200 or 400)
• microstep — Microstep divisor (1, 2, 4, 8, 16, 32, etc.)

Practical Notes

A 200-step motor at 16× microstepping: θ = 360/(200×16) = 0.1125°, giving 3200 microsteps/rev. Practical accuracy of microsteps degrades beyond about 16×-32× due to detent torque, load, and driver current precision. For a 3D printer with 200-step motor, 16× microstepping, and 8 mm lead screw with 2 mm pitch: linear resolution = 2/(200×16) = 0.000625 mm = 0.625 µm per microstep.