Stepper Motor Step Angle Calculator

Stepper motors move in discrete steps rather than continuous rotation. Each electrical pulse from the driver moves the motor shaft by a precise angular increment called the step angle. This makes stepper motors ideal for CNC machines, 3D printers, robotics, and any application requiring precise positioning without encoders.

The fundamental formulas:

Step Angle (°) = 360° ÷ (Number of Pole Pairs × Phases × 2)

For a standard 2-phase motor: Step Angle (°) = 360° ÷ (Number of Teeth on Rotor × 2)

A more practical formula using the number of full steps: Step Angle (°) = 360° ÷ Full Steps Per Revolution

Common step angles:

• 1.8°: most common, = 200 full steps/revolution (50 tooth rotor, 2-phase)
• 0.9°: high resolution, = 400 full steps/revolution (100 tooth rotor)
• 7.5°: older/smaller motors, 48 full steps/revolution
• 15°: toy and simple positioning motors, 24 steps/revolution

Microstepping: Modern stepper drivers (like the A4988, DRV8825, or TMC2208) divide each full step into smaller microsteps by controlling current levels in the windings:

Important note on microstepping torque: Microstepping improves smoothness and reduces vibration but does NOT improve positioning resolution in practice. Torque is significantly reduced at microsteps. For maximum torque, use full or half stepping.

Linear distance per step (for CNC / 3D printers): If the motor drives a leadscrew or belt: mm per step = (Lead of screw OR belt pitch × pulley teeth) ÷ Steps per revolution

Example: 1.8° motor + 1/16 microstepping (3,200 steps/rev) + 2mm pitch leadscrew: mm/step = 2 ÷ 3,200 = 0.000625 mm per step (very precise!)