Layer height is the single dial that trades speed against smoothness, and there is a safe range for every nozzle. This shows you that range, the sensible default, and the magic numbers that land on a full motor step.
How to use it
- Enter your nozzle diameter (0.4mm on most printers).
- Read the safe range: 25 to 75 percent of the nozzle, with the recommended default in the middle.
- Optionally enter your Z motor steps and leadscrew to see the magic numbers that align to a full step.
- Pick a height in range for your part: lower for detail, higher for speed.
What it does
The safe range, not a guess
Too thin and the nozzle drags, too thick and layers do not bond. The tool draws the lines so you stay between them.
Magic numbers
If your Z axis has a lead that does not divide cleanly, some heights sit between full steps and give uneven layers. This finds the ones that do not.
Any nozzle
Put on a 0.6mm or a 0.2mm nozzle and the whole range shifts. Enter the nozzle and it recomputes.
What people use it for
Dialling in a new nozzle
Swapped to a 0.6mm for speed? The old 0.2mm habit is now too thin. See the new range instantly.
Chasing a smooth surface
A display piece or a lithophane wants thin layers. Find how low you can go before the nozzle starts dragging.
Fast draft prints
For a rough test print, push to the top of the range and halve your print time.
Good to know
- First layer excepted: run it thicker (often 0.2 to 0.3mm) for adhesion regardless of the rest of the print.
- Line width is the other half of the story: 100 to 120 percent of nozzle diameter is the usual band, and it interacts with layer height for flow.
- Very thin layers slow a print sharply because there are more of them. Balance detail against time.
- If your printer uses a belted Z or unusual leadscrew, magic numbers change. Enter the real values rather than trusting the 0.04mm rule of thumb.
Questions
What layer height should I use for a 0.4mm nozzle?
Between about 0.1mm and 0.3mm covers almost everything. 0.2mm is the sensible default: fast enough, strong enough, smooth enough. Drop to 0.12mm for detail, push to 0.28mm for speed on chunky parts.
What is the 25 to 75 percent rule?
A reliable layer height sits between 25 and 75 percent of the nozzle diameter. Below 25 percent the nozzle drags on the layer below, above 75 percent the plastic does not bond well to the layer under it.
What are magic numbers?
Layer heights that land exactly on a full step of the Z motor, so every layer is positioned identically. On common 8mm lead, 2mm pitch leadscrews they are multiples of 0.04mm, which is why 0.12, 0.16, 0.20 and 0.24 are popular.
Does layer height change strength?
Thinner layers bond over more surface and are usually a little stronger, but the effect is small. Wall count and infill matter far more. Choose layer height for surface and speed, not strength.
Also called
Looked up as a layer height calculator, a magic numbers calculator, an optimal layer height tool, or a nozzle to layer height guide. It answers how thick each layer should be, and which exact heights print cleanest.