Stepper Steps per mm Calculator
Steps per mm is the firmware setting that tells a 3D printer's stepper driver how many motor steps equal exactly 1 mm of axis movement. Getting this value correct is fundamental to dimensional accuracy. For belt-driven axes (X, Y), it depends on motor steps, microsteps, belt pitch, and pulley tooth count. For lead screw axes (Z, extruder), it depends on motor steps, microsteps, and lead screw pitch. This calculator handles both configurations.
Steps per mm formula
Steps/mm = (Motor steps * Microsteps) / Travel per revolution (mm)
For a GT2 belt with a 20-tooth pulley: travel per rev = 20 * 2 = 40 mm. With a 200-step motor at 16x microsteps: steps/mm = (200 * 16) / 40 = 80 steps/mm. This is the standard value for most Cartesian and CoreXY printers with this drive configuration.
Common steps per mm values
- GT2 belt, 20-tooth pulley, 200-step motor, 16x microsteps: 80 steps/mm
- GT2 belt, 20-tooth pulley, 400-step motor, 16x microsteps: 160 steps/mm
- T8 lead screw (8 mm lead), 200-step motor, 16x microsteps: 400 steps/mm
- M5 threaded rod (0.8 mm pitch), 200-step motor, 16x microsteps: 4,000 steps/mm
- Extruder values vary by gear ratio; typical direct drive is 415 to 500 steps/mm; bowden with 3:1 gear ratio is around 100 steps/mm.
Stepper steps per mm calculator: frequently asked questions
What are steps per mm in 3D printing?
Steps per mm (steps/mm) is the number of stepper motor steps required to move an axis exactly 1 mm. It is set in the printer firmware (Marlin, Klipper) for each axis. Incorrect steps/mm causes dimensional inaccuracy in printed parts.
What are typical steps per revolution for a stepper motor?
Most 3D printer stepper motors are NEMA 17 with 1.8 degree per step, giving 200 full steps per revolution. Some use 0.9 degree motors with 400 steps per revolution for higher resolution.
What microstep settings are common?
Common microstep values are 1 (full step), 2, 4, 8, 16, and 32. Most modern 3D printers use 16 microsteps. Some stepper drivers (TMC2209, TMC2130) support 256 microsteps.
What is the belt pitch for GT2 belts?
GT2 belts have a 2 mm pitch. The travel per revolution depends on the pulley tooth count. A 20-tooth GT2 pulley gives 20 * 2 = 40 mm per revolution. This is the most common configuration on Cartesian and CoreXY printers.
How do I use this for a lead screw axis?
For Z-axes with lead screws, enter the lead screw pitch as the travel per revolution. An M5 rod with 2 mm pitch gives 2 mm/rev. A T8 lead screw with 8 mm lead (4-start, 2 mm pitch) gives 8 mm/rev. Leave the pulley tooth count field at 1 (it does not apply).
Official sources
- Marlin Firmware: Marlin Configuration Reference (steps/mm documentation).
- NIST: Measurement Needs for Additive Manufacturing.
Reviewed by the CalculatorHub team, edited by James Graham, 15 June 2026. See our methodology.