Stepper Motor Calculator — Steps per mm & Resolution

Most printers with GT2 belts and 20-tooth pulleys use 80 steps/mm (at 16x microstepping). Z-axis with T8 lead screws (2mm pitch, 4 starts = 8mm lead) use 400 steps/mm. These are starting values to calibrate from.

Microstepping divides each full step into smaller steps for smoother motion. 16x is standard and offers a good balance. 32x gives slightly smoother motion but can cause missed steps at high speeds. 8x is noisier but more torquey.

Print a calibration cube and measure it with calipers. If the 20mm cube measures 20.1mm, adjust steps/mm: new_steps = old_steps x (target / measured). Repeat until dimensions are within 0.05mm.

Higher steps/mm gives finer positioning resolution. However, the practical limit is set by the nozzle diameter and other mechanical factors. Most printers have more than enough resolution at 80 steps/mm for the XY axes.