Steps per mm Calculator
Work out the axis steps/mm value for a belt-driven or leadscrew-driven 3D printer axis from the motor, microstepping and drive geometry.
Enter Values
Before you rely on this: First-pass guide only. Verify safety-critical or regulated work against the relevant standards, your project requirements and a qualified professional.
How to use this calculator
- Enter your motor's full steps per revolution (200 for a common 1.8° stepper, 400 for a 0.9°) and the driver microstepping (often 16 or 32).
- For a belt axis (usually X and Y), enter the belt pitch and pulley teeth; for a leadscrew axis (usually Z), enter the leadscrew lead in mm per revolution.
- Read the steps/mm value and set it in firmware (M92 on Marlin), then confirm with a measured-movement test.
How it works
Steps/mm = microsteps per revolution / travel per revolution. Microsteps per revolution = motor full steps × microstepping. For a belt, travel per revolution = belt pitch × pulley teeth; for a leadscrew, it is the lead (distance moved per turn).
Worked example
Worked example. A 1.8° motor (200 steps) at 16× microstepping gives 3200 microsteps per revolution. On a GT2 belt (2 mm pitch) with a 20-tooth pulley the belt travels 40 mm per revolution, so steps/mm = 3200 / 40 = 80. Swapping to an 8 mm leadscrew gives 3200 / 8 = 400 steps/mm.
Common mistakes
- Confusing belt pitch with tooth count — GT2 belts have a 2 mm pitch regardless of how many teeth the pulley has.
- Confusing leadscrew pitch with lead: a 4-start screw with a 2 mm pitch has an 8 mm lead, which is the value you enter.
- Filling in both belt and leadscrew fields; enter only the one that matches the axis.
Frequently asked questions
Is this the same as extruder E-steps?
The idea is identical, but the extruder is driven through a hobbed gear or gearbox rather than a belt or leadscrew, so its steps/mm is best found by the direct extrude-and-measure method in the E-steps calibration tool.
Why is my measured value slightly different from the calculated one?
Belt stretch, pulley tolerance and leadscrew lead error all shift the real value a little. Use this figure as the starting point, then command a known move, measure the actual distance and fine-tune.
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Tip: Enter any known values to calculate the remaining results.
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