How to Calibrate Your Extruder (E-Steps) Step-by-Step

Ever look at a finished print and wonder why the top surface has gaps, or why the walls feel frail and crumbly? You might be suffering from under-extrusion. Conversely, if your nozzle is dragging through blobs of plastic, you’re dealing with over-extrusion.

While many slicer settings can tweak flow, they are just band-aids if your machine’s mechanical baseline is wrong. Your printer needs to know exactly how many steps the motor must turn to push 1 millimeter of filament. This setting is called E-Steps (Extruder Steps per mm).

Because every manufactured gear and motor is slightly different, stock settings are rarely perfect. This guide will walk you through calibrating your extruder to ensure that when you ask for 100mm of plastic, you get exactly 100mm.

Why Calibration Matters

Your extruder is the heart of the delivery system. If the firmware thinks 400 steps equals 100mm of filament, but mechanically it only pushes 95mm, every single line of your print will be 5% starved of material.

• Too Little (Under-Extrusion): Weak parts, gaps between lines, poor layer adhesion.
• Too Much (Over-Extrusion): Blobs, stringing, poor dimensional accuracy, and nozzle dragging.

Calibrating E-steps sets a perfect "mechanical zero" for your slicer to work with.

Step 1: Mark Your Filament

First, we need to create a physical reference point to measure how much filament actually moves.

1. Load filament into your printer.
2. Use a ruler or tape measure to measure 110mm from the exact point where the filament enters the extruder (the intake hole).
3. Mark this spot clearly with your permanent marker.

Step 2: Get Your Current E-Steps

Connect your printer to your computer and open your terminal software (e.g., Pronterface).

1. Connect to the printer (ensure the correct COM port and Baud rate, usually 115200 or 250000).
2. Type M503 and hit Send.
3. Look through the output log for a line starting with M92. It will look something like this:
   echo: M92 X80.00 Y80.00 Z400.00 E93.00
4. Write down the number after the E. In this example, it is 93.00. This is your Current E-Step Value.

Step 3: The Extrusion Test

Now we need to push plastic.

1. Preheat: Send M109 S200 (for PLA) or use your printer’s preheat menu. Wait for it to reach temperature.
2. Set Relative Mode: Send command M83.
   Why? This tells the printer "move 100mm from right here" rather than "move to the 100mm coordinate." If you skip this, the extruder might wind backwards or do nothing.
3. Extrude: Send command G1 E100 F100.
   Command Breakdown

   G1: Move Extruder
   E100: Extrude 100mm
   F100: Feed rate (speed) of 100mm/min. Slow is better for accuracy.

4. Wait: The gears will turn slowly. Wait for the motion to stop completely.

Step 4: Measure and Calculate

Once the motor stops, measure the distance from the extruder intake to the mark you made in Step 1.

• Ideal Scenario: You measure exactly 10mm. (110mm start - 100mm extruded = 10mm left).
• Real World: You will likely measure something else, like 12mm (under-extrusion) or 8mm (over-extrusion).

The Formula

We need to calculate how much filament was actually extruded, and use that to find the new steps.

1. Calculate Actual Extrusion:
   110mm (Start) - [Your Measurement] = Actual Extruded Length
   Example: If you measured 12mm left: 110 - 12 = 98mm actually extruded.
2. Calculate New E-Steps:
   (Current E-Steps × 100) / Actual Extruded Length = New E-Steps

Example:

• Current E-Steps: 93
• Requested: 100mm
• Actual: 98mm
• (93 × 100) / 98 = 94.90
• New E-Step Value: 95

Step 5: Update Your Printer

Now that you have the magical number, you need to tell the printer.

1. In your terminal, type M92 E[New Value]
   Example: M92 E95
2. Critical Step: Type M500 and hit Send.
   You should see a message like Settings Stored. If you forget M500, the printer will forget your calibration as soon as you turn it off!

Verify Your Results

It is good practice to repeat the test once with the new values.

1. Mark the filament at 110mm again.
2. Run the extrusion test again.
3. Measure the remaining filament.
4. If it is within roughly 9.8mm to 10.2mm, you are calibrated!