Layer height for a 0.8 mm nozzle: 0.16 to 0.64 mm, 0.40 mm first layer

A 0.8 mm nozzle prints layers from 0.16 to 0.64 mm (20% to 80% of its diameter), and Bambu Studio and PrusaSlicer both default to 0.40 mm. Bambu Lab stops at 0.56 mm and lays the first layer at 0.40 mm; Prusa’s MK4S and CORE One presets use 0.20 mm. Expect lower speeds in mm/s than on a 0.4 mm nozzle: each millimeter of line at 0.40 mm carries 3.6 times the plastic of a 0.4 mm nozzle’s line at 0.20 mm, and the slicer caps plastic per second.

What layer height should you use with a 0.8 mm nozzle?

Use 0.16 to 0.64 mm (20% to 80% of the nozzle diameter) and start at 0.40 mm, the 0.8 mm default in Bambu Studio and PrusaSlicer. On a Bambu Lab printer, stay between 0.16 and 0.56 mm. Bambu Lab sets that 70% ceiling in its 0.8 mm printer profiles, and Bambu Studio warns at any higher value.

Limit	Share of the nozzle	0.8 mm nozzle
Minimum, OrcaSlicer and Bambu Lab	20%	0.16 mm
Bambu Lab maximum	70%	0.56 mm
Prusa maximum	70 to 80%	0.56 to 0.64 mm
OrcaSlicer maximum, UltiMaker Cura warning	80%	0.64 mm

OrcaSlicer’s wiki gives the reasons for the range: flow inconsistencies and “fish scale” patterns below 20%, weak layer adhesion above 80%.

Type 0.60 mm in Bambu Studio and it warns that the value exceeds Printer Settings > Extruder > Layer height limits, then offers to change it to 0.56 mm. The layer height limit error article covers that dialog. PrusaSlicer’s Original Prusa MK4S and Prusa CORE One 0.8 mm printer profiles list limits of 0.20 to 0.60 mm, but they only cap variable layer height and support layers.

Set the value under Process > Quality > Layer height in Bambu Studio, or Print Settings > Layers and perimeters > Layer height in PrusaSlicer. The layer height calculator gives the same range for any nozzle.

Presets for a 0.8 mm nozzle in each slicer

Select the 0.8 mm printer profile first, such as “Bambu Lab X1 Carbon 0.8 nozzle” or “Original Prusa MK4S 0.8 nozzle”. Both slicers show the 0.8 mm print presets only for that printer profile.

Slicer and printers	Layer height presets	Default	Line width
Bambu Studio: X1 Carbon, X1, X1E, P1S	0.24, 0.32, 0.40, 0.48 and 0.56 mm Standard	0.40 mm	0.82 mm
Bambu Studio: A1, A1 mini, P1P	0.24 mm Fine, 0.32 mm Optimal, 0.40 mm Standard, 0.48 mm Draft, 0.56 mm Extra Draft	0.40 mm	0.82 mm
Bambu Studio: H2D, H2D Pro, H2S, H2C, P2S, X2D, A2L	0.24 and 0.32 mm Balanced presets, 0.40 mm Standard	0.40 mm	0.82 mm
PrusaSlicer: MK4S, CORE One	0.30 mm DETAIL, 0.40 mm QUALITY, 0.55 mm DRAFT; SPEED and STRUCTURAL at the same heights for the HF0.8 (High Flow 0.8 mm) nozzle	0.40 mm	0.9 mm, 1 mm for 0.55 mm perimeters
UltiMaker Cura: UltiMaker S5, AA 0.8, PLA	0.2 mm Fast, 0.3 mm Extra Fast, 0.4 mm Sprint	not listed	0.8 mm

Line width for a 0.8 mm nozzle

The presets above print 0.82 to 0.9 mm lines. With the width fields at 0, PrusaSlicer and Bambu Studio print perimeters and infill 1.125 × 0.8 = 0.9 mm wide. UltiMaker Cura uses the nozzle size, 0.8 mm. Prusa’s guide to nozzle profiles suggests about 110% of the nozzle, 0.88 mm. The line width calculator turns these widths into wall thicknesses.

What first layer height should you use with a 0.8 mm nozzle?

Use 0.40 mm, half the nozzle diameter. Every Bambu Studio 0.8 mm preset prints its first layer at that height with 0.82 mm lines. Stay at or under 0.52 mm, OrcaSlicer’s 65% ceiling. Prusa’s MK4S and CORE One 0.8 mm presets go thinner: 0.20 mm, with a 1 mm wide first line.

Slicer or maker	First layer height	First layer line width
Bambu Studio, all 0.8 mm presets	0.40 mm (50%)	0.82 mm
OrcaSlicer wiki	0.45 mm in its quick reference, 0.52 mm at most (65%)	not listed
PrusaSlicer, MK4S and CORE One 0.8 mm presets	0.20 mm	1 mm
PrusaSlicer, MK3 and MK2.5 “@0.8 nozzle” presets	0.30 mm	0.9 mm
UltiMaker Cura, UltiMaker S5 with AA 0.8	0.2 mm, or the layer height if larger	0.8 mm

Bambu Lab’s wiki states the rule behind its presets: first layer height = nozzle diameter × 50%. PrusaSlicer’s tooltip gives the reason for a thicker first layer: better adhesion and more tolerance for a build plate that is not perfectly flat.

On the MK4S and CORE One, Prusa widens the line rather than thickening the layer, and keeps the 0.20 mm first layer its other nozzles use. The 1 mm first line is 125% of the nozzle, inside the 120 to 140% that Prusa’s nozzle guide suggests for bed adhesion.

1. Set Initial layer height in Bambu Studio, or First layer height in PrusaSlicer, to 0.40 mm. Both fields sit next to Layer height in the same settings group.
2. Check the first layer again. Prusa notes that changing the first layer height “will most likely require adjusting the calibration of the first layer”.

How fast can a 0.8 mm nozzle print at 0.40 mm layers?

With PLA on a standard hotend, 53 to 64 mm/s in the profiles below, whatever the speed fields say. The filament’s max volumetric speed (the most plastic per second the slicer allows) sets the pace. Bambu Lab’s wiki gives the flow formula:

flow (mm³/s)     = layer height × line width × print speed
max speed (mm/s) = max volumetric speed ÷ (layer height × line width)

Worked example: Bambu Lab X1 Carbon

1. Cross-section of a 0.40 mm layer and 0.82 mm line: 0.40 × 0.82 = 0.328 mm².
2. The 0.40mm Standard preset sets inner walls to 150 mm/s: 0.328 × 150 = 49.2 mm³/s.
3. Bambu Studio’s Bambu PLA Basic profile for the X1 Carbon 0.8 nozzle allows 21 mm³/s, so those walls slow to 21 ÷ 0.328 = 64 mm/s.
4. On a 0.4 mm nozzle the same filament also gets 21 mm³/s. A 0.20 mm layer with 0.45 mm lines is 0.09 mm², so inner walls set to 300 mm/s run at 21 ÷ 0.09 = 233 mm/s.

The 0.8 mm line holds 0.328 ÷ 0.09 = 3.6 times the plastic per millimeter, so at the same 21 mm³/s it moves 3.6 times slower. Bambu Lab’s wiki explains that a tall layer has a large extrusion flow, and “a slower printing speed is required to make the hot end fully melt the extruded filament.”

The same check on PrusaSlicer’s MK4S presets, with the Prusament PLA limit each profile carries:

Profile	Layer × line	Infill speed set	Flow needed	Filament limit	Speed at the limit
0.40mm QUALITY @MK4S 0.8	0.40 × 0.9 mm	90 mm/s	32.4 mm³/s	19 mm³/s	53 mm/s
0.40mm SPEED @MK4S HF0.8	0.40 × 0.9 mm	130 mm/s	46.8 mm³/s	36 mm³/s	100 mm/s

These figures treat the line as a plain rectangle. Bambu Studio and PrusaSlicer model it with rounded sides, which holds a little less plastic, so their own speed lands 10 to 12% higher: 72 mm/s rather than 64 mm/s in the X1 Carbon example.

How to print faster with a 0.8 mm nozzle

• A hotend with more melt capacity. Bambu Lab lists its High Flow hotend for the H2D, H2S, H2C, P2S and X2D at 40 mm³/s with a 0.8 mm nozzle, for PLA Basic, PLA Matte and PETG HF. That allows 40 ÷ 0.328 = 122 mm/s at 0.40 mm. On a Prusa, the HF0.8 nozzle in the table above does the same job.
• A measured flow limit. Bambu Lab’s wiki warns that a raised max volumetric speed can make the printer try to extrude faster than its hardware allows. Measure your hotend and convert the result with the volumetric flow calculator.
• A thinner layer. At 0.24 mm the same 21 mm³/s allows 21 ÷ (0.24 × 0.82) = 107 mm/s.

The limit sits in the filament preset: Filament tab > Volumetric speed limitation > Max volumetric speed in Bambu Studio, and Filament Settings > Advanced > Print speed override > Max volumetric speed in PrusaSlicer. After slicing, Bambu Studio’s Flow view shows where the print hits the cap.

What is a 0.8 mm nozzle good for?

Large, strong parts printed fast. Bambu Lab’s nozzle comparison lists 0.6 and 0.8 mm nozzles for “faster speeds” and high-performance filaments, “with some decrease in resolution”.

Prusa says nozzles larger than 0.6 mm print faster but limit fine detail, and that functional parts “may prove stronger since each line has a larger amount of solid material”. It also warns that the extra plastic to cool can increase warping in ASA (acrylonitrile styrene acrylate) or PC Blend.