E-Steps Calibration Calculator
Dial in your extruder so it feeds exactly the filament it's told to. Command a known length, measure what actually fed, and this gives the corrected steps per millimetre — plus the M92 command to set it.
Read current E-steps with M503 (look for the M92 E line), or from your printer's config.
Measure directly how much filament the extruder pulled in during the commanded move.
Mark the filament this far above the extruder inlet, extrude, then measure the remaining distance to the mark. Fed = mark − leftover.
Formula & how it works
Corrected E-steps = current E-steps × commanded ÷ actually fed. If less fed than commanded, the value goes up; if more, it goes down.
In mark-and-leftover mode, actually fed = mark distance − leftover.
Worked example
Your printer is set to 93 steps/mm. You command 100 mm but only 95 mm actually feeds. The corrected value is 93 × 100 ÷ 95 = 97.89 steps/mm. You would send M92 E97.89 and then M500 to save it, then extrude 100 mm again to confirm it now feeds a full 100.
Getting a clean calibration
Measure at printing temperature
Cold filament feeds differently from hot, so heat the hotend to your normal printing temperature before extruding. Extrude slowly — around 1 to 2 mm per second — so the motor is not fighting back-pressure, which can skew how much actually feeds and throw off the number.
Mark high and measure carefully
Marking the filament well above the extruder inlet, often 100 to 120 mm, keeps your mark clear of the machine so you can measure the leftover accurately. A caliper beats a ruler here; even half a millimetre of error at 100 mm is a noticeable extrusion shift across a whole print.
Confirm, then move on to flow
After setting the new value, run the test once more — a well-calibrated extruder should feed within a fraction of a millimetre of the command. E-steps fix how much filament enters the hotend; fine-tuning how much plastic lands on the part is the job of flow-rate calibration, which is the natural next step.