E-steps calculator

E-steps (steps per millimeter on the E axis) tell the firmware how far to turn the extruder motor to push a given length of filament. If the value is off, every print is over- or underextruded: blobs, rough top surfaces and dimensional errors on one side, gaps and weak layers on the other.

It is worth checking after you change the extruder, gears or stepper driver, or if you can't get a good print no matter how you tune flow in the slicer. Calibrate e-steps first; then fine-tune flow per filament with the flow calculator.

1. Heat the hotend to the normal printing temperature for your filament.
2. Measure 120 mm up from the extruder inlet and mark the filament with a fine marker.
3. Send M83 (relative extrusion), then G1 E100 F100 to extrude 100 mm slowly.
4. Measure the distance from the inlet to the mark again.
5. Enter the numbers in the calculator.

If the extruder pushed exactly 100 mm, 20 mm will be left. In Marlin, find the current value in the M503 output on the line M92 X… Y… Z… E93.00. In Klipper, it is rotation_distance in the [extruder] section of printer.cfg.

Marlin: new e-steps = old e-steps × requested ÷ actual

Klipper: new rotation_distance = old rotation_distance × actual ÷ requested

actual = mark distance − remaining distance

Example: e-steps 93, mark at 120 mm, 24 mm remaining after the test. The extruder actually pushed 96 mm instead of 100 (−4%).

• Marlin: 93 × 100 ÷ 96 = 96.88 steps/mm. Send M92 E96.88 and M500 to save.
• Klipper with rotation_distance 33.5: 33.5 × 96 ÷ 100 = 32.16. Edit printer.cfg and RESTART.

The Klipper ratio is inverted because rotation_distance is millimeters per motor revolution, the opposite of steps per millimeter.

• Use a slow feed rate (F100 or lower) so the hotend can melt the filament fully; extruding fast through a hot nozzle can make the extruder slip and skew the test.
• Measure with calipers, not a ruler, and read the distance at the same edge of the mark both times.
• Repeat the test with the new value until 100 mm requested gives 99–101 mm.
• Differences under 1% are within measurement error; the calculator tells you when a change isn't worth making.
• Some printers lock e-steps in firmware or reset them on reboot; M500 saves the value to EEPROM where supported.

Once e-steps are right, the remaining differences between filaments are handled with the flow rate (extrusion multiplier) in your slicer. A printer with correct e-steps usually needs a flow of roughly 90–100% depending on the material. Then check your maximum volumetric speed so fast prints don't underextrude. The calculator runs in your browser and nothing is sent to the printer automatically.

Typical starting values help you spot a typo: many geared direct-drive extruders sit around 400–700 steps/mm, while common non-geared Bowden extruders are often around 90–100 steps/mm. If your result is far outside the range for your hardware, re-measure before saving.