Steps Per MM Calculator

What is Steps Per MM?

Steps per millimeter (steps/mm) is a critical calibration value for 3D printers, CNC machines, and other motion control systems. It tells the controller exactly how many motor steps are needed to move the axis by one millimeter.

Getting this value correct ensures your machine produces accurate, dimensionally precise parts. Too few steps per mm results in oversized prints, while too many creates undersized parts.

How to Calculate Steps Per MM

For Belt Drives

[\text{Steps/mm} = \frac{\text{Motor Steps} \times \text{Microstepping}}{\text{Belt Pitch} \times \text{Pulley Teeth}}]

For Lead Screws

[\text{Steps/mm} = \frac{\text{Motor Steps} \times \text{Microstepping}}{\text{Lead (mm/rev)}}]

Where:

• Motor Steps is the full steps per revolution (typically 200 for 1.8-degree motors)
• Microstepping is the driver microstepping setting (1, 2, 4, 8, 16, 32)
• Belt Pitch is the distance between belt teeth in mm (GT2 = 2mm)
• Pulley Teeth is the number of teeth on the motor pulley
• Lead is the linear travel per screw revolution

Calculation Examples

Belt Drive Example (Typical 3D Printer X/Y Axis)

Given:

• Motor Steps: 200 (1.8-degree motor)
• Microstepping: 16
• Belt Pitch: 2mm (GT2 belt)
• Pulley Teeth: 20

[\text{Steps/mm} = \frac{200 \times 16}{2 \times 20} = \frac{3200}{40} = 80]

This is why 80 steps/mm is the standard value for many 3D printers.

Lead Screw Example (Typical Z Axis)

Given:

• Motor Steps: 200
• Microstepping: 16
• Lead: 8mm (common T8 lead screw)

[\text{Steps/mm} = \frac{200 \times 16}{8} = \frac{3200}{8} = 400]

Common Values Reference

Fine-Tuning Your Calibration

After calculating the theoretical steps/mm:

1. Print a calibration cube (e.g., 20mm x 20mm x 20mm)
2. Measure the actual dimensions with calipers
3. Adjust using: New Steps/mm = Current Steps/mm × (Expected / Measured)
4. Re-test and repeat if necessary