Flow Rate

Also known as: Extrusion Multiplier, Flow Multiplier, Flow Percentage

intermediate Slicer Settings ⚙️ Slicer Setting

A multiplier that adjusts how much filament is extruded, fine-tuning for material variations.

Flow rate (or extrusion multiplier) adjusts the amount of filament extruded. It’s a percentage multiplier applied to calculated extrusion amounts to compensate for material variations.

Why Adjust Flow Rate

  • Filament diameter varies between brands
  • Different materials flow differently
  • Temperature affects viscosity
  • Fine-tune dimensional accuracy

Calibrating Flow Rate

  1. Set wall line count to 1
  2. Set infill to 0%
  3. Print 20mm cube
  4. Measure wall thickness with calipers

Calculate Correction

New Flow = (Expected / Actual) × Current Flow

Example:

  • Nozzle: 0.4mm, expected wall: 0.4mm
  • Measured wall: 0.44mm
  • New flow = (0.4 / 0.44) × 100% = 91%

Material Defaults

Different materials often need different flow:

  • PLA - 95-100%
  • PETG - 95-100%
  • ABS - 95-100%
  • TPU - 100-110%

Signs of Wrong Flow

Under-extrusion (flow too low)

  • Gaps in top layers
  • Weak layer adhesion
  • Thin walls

Over-extrusion (flow too high)

  • Bulging lines
  • Rough surfaces
  • Blobs and zits
  • Dimensional inaccuracy

Tip

Calibrate E-steps first, then adjust flow rate. E-steps are hardware calibration; flow rate is material fine-tuning.