Stepper Motor Steps per mm Calculator
The steps-per-millimetre value tells the firmware how many motor steps move an axis one millimetre, and it must be set correctly for accurate prints and cuts. This calculator takes the motor's full steps per revolution, the microstepping multiplier, and the distance the axis travels per motor revolution, and returns the steps per millimetre along with the total steps per revolution. It works for belt-and-pulley axes and leadscrew axes alike.
Steps per mm formula
Steps per revolution = full steps * microstepping multiplier
Steps per mm = steps per revolution / distance per revolution
Belt distance per revolution = pulley teeth * belt pitch
Leadscrew distance per revolution = screw lead
Compute the distance per revolution from your drive type, then divide the total steps per revolution by it to get steps per millimetre.
Worked example
A 1.8 degree motor (200 full steps) at 16 microsteps on a 20-tooth GT2 pulley (40 mm per revolution): steps per revolution = 200 * 16 = 3,200. Steps per mm = 3,200 / 40 = 80.00.
Steps per mm: frequently asked questions
How do I calculate steps per mm?
Steps per mm equals the motor's full steps per revolution times the microstepping multiplier, divided by the distance the axis moves in one motor revolution. For a belt axis the distance per revolution is the pulley tooth count times the belt pitch; for a leadscrew it is the screw lead.
What is the distance per revolution for a belt drive?
For a GT2 belt (2 mm pitch) on a 20-tooth pulley, one revolution moves 20 times 2 = 40 mm. Enter that 40 mm as the distance per revolution. For a leadscrew, enter its lead, for example 8 mm for a common 4-start, 2 mm pitch screw.
Why does microstepping matter?
Microstepping divides each full step into smaller increments for smoother motion, multiplying the steps per revolution. A 1.8 degree motor has 200 full steps per revolution; at 16 microsteps that becomes 3,200 steps per revolution. The steps per mm scale with this multiplier.
Official sources
- U.S. National Institute of Standards and Technology: Physical Measurement Laboratory (length and motion metrology).
- The steps-per-mm relationship follows from dividing the steps in one revolution by the distance moved per revolution.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.