Maker and DIY Calculators

Steps per mm calculator.

Firmware needs to know how many motor steps move an axis one millimetre. Enter your motor, microstepping and mechanics to get the number for a belt, lead screw or extruder.

Steps per mm = (motor full steps per revolution x microsteps) / travel per motor revolution. A 200-step motor at 16 microsteps on a 2 mm pitch belt with a 20 tooth pulley moves 40 mm per revolution: 3,200 / 40 = 80 steps/mm.

Motor and mechanics

Axis type

Motor full steps per revolution

steps

200 for a 1.8 degree motor, 400 for a 0.9 degree motor (360 / step angle).

Microstepping

The driver setting, for example 16.

Belt pitch

Distance between belt teeth, from the belt's spec.

Pulley teeth

teeth

Thread pitch

Distance between neighbouring thread crests on the screw.

Thread starts Independent threads on the screw. Lead = pitch x starts; 1 for a single-start screw.

Effective drive gear diameter

Diameter at the filament contact, from your extruder's spec or measured. Use E-steps calibration to fine-tune.

Gear reduction ratio

: 1

1 for direct drive; for example 3 for a 3:1 geared extruder.

Steps per mm

Fill the form and press Calculate.

Worked example

Belt axis: a 200-step motor at 16 microsteps makes 200 x 16 = 3,200 microsteps per revolution. A belt with 2 mm pitch on a 20 tooth pulley moves 2 x 20 = 40 mm per revolution, so 80 steps/mm, a resolution of 0.0125 mm. Lead screw: a screw with 2 mm thread pitch and 4 starts has an 8 mm lead, so 3,200 / 8 = 400 steps/mm. These are example values; use the specification of your own parts.

How it works

The number of steps for one millimetre is the steps for one full turn divided by the millimetres one turn moves the axis. Steps per turn is the motor's full steps times the driver's microstepping. Travel per turn is pitch times teeth for a belt, the lead for a screw, and the circumference of the drive gear divided by any gear reduction for an extruder.

In firmware, M92 sets the number of steps per unit (usually per mm) for each axis. After changing hardware, check by moving a known distance and measuring, and adjust if the real movement differs.

Sources (opened 2026-10-08). M92 - Set Axis Steps-per-unit | Marlin Firmware for M92 setting the number of steps-per-mm (or per inch or degree) for one or more axes, including E for the extruder. The formula is geometry and arithmetic; the example values are not a recommendation.

FAQ

How do I calculate steps per mm?

Multiply the motor full steps per revolution by the microstepping, then divide by the millimetres the axis moves for one motor revolution.

How many steps does my motor have?

A 1.8 degree motor has 360 / 1.8 = 200 full steps per revolution, and a 0.9 degree motor has 400.

What is the lead of a lead screw?

Lead is how far the nut moves in one revolution. It equals the thread pitch times the number of starts, so a 2 mm pitch four-start screw has an 8 mm lead.

How do I set the value in firmware?

On Marlin-style firmware use M92 followed by the axis letter and the number, such as M92 X80, and save with M500. Other firmware sets steps per mm in its own configuration.

Why do I need to check by measuring?

Real hardware varies, belts stretch and extruder gears bite the filament at an effective diameter you may not know exactly. Move a known distance and measure to confirm.

Disclaimer

Estimates from the numbers you enter. Check the result by moving the axis a known distance before relying on it, and follow your machine maker's instructions for firmware changes.