Extrusion Width Calculator
Calculate the recommended extrusion width for your nozzle diameter. Enter your nozzle size and the percentage to see the resulting extrusion width in mm.
Last updated: May 2026
Enter nozzle diameter and percentage to calculate extrusion width.
Extrusion width reference table
| Nozzle | 100% (min) | 110% | 120% (standard) | 150% (wide) |
|---|---|---|---|---|
| 0.2 mm | 0.20 mm | 0.22 mm | 0.24 mm | 0.30 mm |
| 0.25 mm | 0.25 mm | 0.275 mm | 0.30 mm | 0.375 mm |
| 0.4 mm | 0.40 mm | 0.44 mm | 0.48 mm | 0.60 mm |
| 0.6 mm | 0.60 mm | 0.66 mm | 0.72 mm | 0.90 mm |
| 0.8 mm | 0.80 mm | 0.88 mm | 0.96 mm | 1.20 mm |
| 1.0 mm | 1.00 mm | 1.10 mm | 1.20 mm | 1.50 mm |
What extrusion width does
Extrusion width controls how wide each line of plastic is laid down. The nozzle diameter is the physical minimum, you cannot extrude a line narrower than the nozzle opening. But you can extrude wider by pushing more material through: the slicer increases the extrusion multiplier while the nozzle moves at the same speed.
A wider extrusion line overlaps more with adjacent lines, which improves layer bonding and closes gaps more reliably. The trade-off is reduced sharpness on fine details and corners. Most slicer defaults sit at 100-120% of nozzle diameter. PrusaSlicer defaults to 0.45 mm for a 0.4 mm nozzle (112.5%). OrcaSlicer and Bambu Studio typically default to 0.42 mm (105%).
When to adjust extrusion width
- 100% (match nozzle diameter): Best for fine surface detail, decorative prints, thin walls
- 110-120%: General-purpose default, good layer adhesion with minimal impact on detail
- 130-150%: Structural parts, single-wall vase mode, gap-filling; faster prints, coarser edges
- Above 150%: Rarely needed; risk of poor surface quality and corner rounding
Line width: the number the flow calculator actually wants
Extrusion width is not a cosmetic setting. It is the precise input that drives the volumetric flow calculation. The flow calculator needs line width times layer height times speed, and if you feed it the nozzle diameter as a shortcut the number comes out a few percent low. That gap is small enough to ignore at slow speeds, and large enough to matter when you are running close to your hotend's ceiling.
Extrusion width sits in the middle of the calibration sequence, with exactly one input upstream and one downstream check that consumes it. Before arriving here, the nozzle diameter has been chosen (see the nozzle diameter decision guide, the nozzle size chart, or the nozzle size comparison) and layer height has been capped at or below 75% of that nozzle diameter so the layer can actually be squished flat (the layer height guide explains the quality-versus-speed trade-off there). Those two upstream decisions land on your desk as fixed numbers. What this calculator does is convert nozzle diameter plus a percentage (somewhere in the 100 to 120% band for most prints) into a precise millimetre value: that mm figure is what the downstream check demands. You are here. The reason precision matters is that layer height x line width x print speed equals volumetric flow, and the volumetric flow calculator will give you a misleading number if you substitute the raw nozzle diameter for the actual line width. Once flow confirms you are under the hotend ceiling, those parameters are ready to be locked in as a slicer profile (see what slicer presets actually change); if gaps or banding appear after that, the cause is almost never the line width itself, and the underextrusion guide traces the real culprits.
A note from the bench: on the Ender 3 with its stock hotend, even a small overestimate of line width, combined with aggressive layer height, can push the flow calculation past the safe ceiling before the slicer's speed slider looks obviously wrong. Getting the exact mm from this calculator, rather than eyeballing 120% of 0.4 as "roughly 0.48", is the difference between a clean profile and one that starves a few hundred layers in.
Frequently Asked Questions
What extrusion width should I use for standard prints?
110-120% of nozzle diameter is a safe default for most prints. For a 0.4 mm nozzle that's 0.44-0.48 mm. This range gives slightly better layer adhesion than 100% without visibly affecting surface quality or sharp edges. If your slicer already has a sensible default (like PrusaSlicer's 0.45 mm for a 0.4 mm nozzle), there's no need to change it.
Can I set extrusion width narrower than my nozzle diameter?
No. The nozzle diameter is the physical minimum, plastic cannot be extruded through a hole wider than the opening without spreading laterally. Entering a value below 100% in your slicer will either be ignored, corrected automatically, or cause under-extrusion as the slicer tries to compensate with an impossible flow rate.
Why would I use a wider extrusion width for structural parts?
Wider extrusions (130-150%) push more material into each line, which increases overlap between adjacent perimeters and infill lines. This improves bonding and reduces the chance of gaps or voids in the print. The resulting part is often stiffer in the XY plane. The trade-off is visible blobbing at corners and less precise outer surfaces.
Does extrusion width affect print speed?
Wider extrusion width effectively increases throughput, the printer can cover more area per pass, so it needs fewer passes. This can reduce print time by 10-30% at 120-150% extrusion width compared to 100%, especially on infill. The actual nozzle travel speed doesn't change; only the volume of material per mm of travel changes.
Should I use the same extrusion width for perimeters and infill?
Not necessarily. Most slicers let you set different extrusion widths per feature type. A common setup: outer perimeter at 100% (for surface quality), inner perimeters at 110-120% (for adhesion), and infill at 120-150% (for speed). This gives better surface finish without sacrificing structural integrity or print time.