Layer height vs nozzle size

Drag the sliders and watch a nozzle cross-section lay down the layer lines live — with the nozzle aperture, the extruded bead (line) width and the layer height all dimensioned. See the recommended layer height for your nozzle, and what you trade away going finer or faster.

● Pure front-end — no uploads, nothing stored

Section view: the nozzle extruding layer lines, to scale (nozzle body stylised)

0.40 mm
0.20 mm
0.45 mm
113% of nozzle · typical 100–120%
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Layer ÷ nozzle
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Overall
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Line width
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Line ÷ nozzle
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Print time vs 0.2 / 0.45 mm
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Layers for a 20 mm part
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Surface finish
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Layer bonding
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How to read this

Layer height is the thickness of each printed slice; nozzle diameter is the orifice the plastic is pushed through. The two are linked: a layer must be thin enough that the nozzle can press it onto the layer below. The widely-used guideline is to keep layer height at 25–65% of the nozzle diameter for quality prints, with roughly half the nozzle width as the sweet spot; 65–80% is coarse "draft" territory and above about 80% adhesion and reliability fall apart. Below 25% you get lovely detail but very slow prints. Thinner layers mean smoother curves and finer detail but many more layers — and print time rises almost in proportion. Line width is a separate slicer setting, normally 100–120% of the nozzle diameter: the flat of the nozzle squashes each bead outward into a flat-topped oval that is wider than the orifice, and a higher flow / extrusion multiplier widens it further. The time, surface-finish and bonding readouts are relative guides based on published rules of thumb, not a firmware-exact simulation.

Frequently asked

What's the best layer height for a 0.4 mm nozzle?
Roughly 0.10–0.30 mm (25–75% of the nozzle), with 0.20 mm as the everyday sweet spot. Drop to 0.12 mm or below for fine detail; push 0.28–0.32 mm for fast, strong drafts.
Why is the line width bigger than the nozzle?
The nozzle's flat tip squashes each extruded bead outward into a flat-topped oval that's wider than the orifice. Line width is a slicer setting, typically 100–120% of the nozzle — a 0.4 mm nozzle usually prints a 0.4–0.48 mm line (0.45 mm is a common default). More flow widens it further.
How does layer height affect print time?
Almost inversely — halving the layer height roughly doubles the layer count and the print time. 0.2 mm → 0.1 mm is about 2× longer; 0.2 mm → 0.3 mm is about a third faster.
Does a thinner layer make a stronger print?
Not necessarily. Thinner layers improve detail but add more inter-layer bonds. Within the recommended range, moderate-to-thick layers often bond as well or better. Wall count, temperature and infill matter more for strength than layer height alone.
Can the layer height be bigger than the nozzle?
No — it must stay under the nozzle diameter, practically below ~80% of it, or the nozzle can't press each layer onto the one below and adhesion fails.

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